List of Arthur characters

This is a list of characters featured in the PBS Kids television show Arthur, which is based on the book series by Marc Brown.

Arthur, the titular character, is the chief protagonist in the series. Buster, Francine, Muffy, Binky, the Brain, Sue Ellen, Mr. Ratburn, D.W., Kate and Arthur's parents are the major characters. Over the years, the roles of each character have changed and expanded as more episodes have focused on other characters besides the notable and major ones. Minor characters such as Fern, George, Prunella, The Tibble Twins, Emily, and Jenna, have gradually expanded roles in the series. Each of the characters are animals.

Children

• Arthur Timothy Read (voiced by Michael Yarmush 1996–2000, 2022; Justin Bradley 2001; Mark Rendall 2002–2003, 2001 redub; Kye Sones 2002–2012, 2001 redub; Cameron Ansell 2004–2007; Dallas Jokic 2008–2012; Drew Adkins 2012–2014; William Healy 2014–2016; Jacob Ursomarzo 2016–2018; Roman Lutterotti 2019–2022) is an aardvark who attends third grade at Lakewood Elementary in Elwood City. He has two younger sisters, D.W. and Kate, and a dog named Pal. He plays the piano, wears a yellow cotton sweater, white dress shirt, blue jeans, and round brown glasses.
• Dora Winifred Read (usually known as D.W.) (voiced by Michael Caloz 1996–1998; Oliver Grainger 1999–2001; Jason Szwimer 2002–2006; Mariella Miller 2002–2012; Luciano Rauso 2006; Ryan Ehrenworth 2007; Robert Naylor 2007–2012; Jake Beale 2012–2014; Andrew Dayton 2014–2016; Christian Distefano 2016–2018; Ethan Pugiotto 2019–2022; Nissae Isen 2022) is a four (later five)-year-old brown-haired middle child of the Read family who usually wears a white, long-sleeved blouse and a pink sleeveless knee-length dress. She attends preschool and enjoys watching the TV show "Mary Moo Cow" and listening to the song "Crazy Bus," much to Arthur's annoyance. Unlike most children her age, D.W. is fully literate and reads complex material in several episodes. The special episode, "The Rhythm and Roots of Arthur," reveals that D.W. was named after Grandma Thora's aunt Dora Winifred, who died before she was born. She can be bossy, selfish, arrogant, spiteful, and often downright wrathful, especially towards her brother. Despite this, she has a good heart. According to Marc Brown, D.W. is inspired by his own experiences with his own three little sisters (and especially Kim Brown.). When she is introduced as an adult in the series finale "All Grown Up," it is confirmed that she has taken up the profession of law enforcement. It is also confirmed in the episode "Arthur's First Day" that she hates the name Dora Winifred.
• Kate Read (voiced by Tracy Braunstein) is Arthur and D.W.'s baby sister. She can communicate with Pal, Mei-Lin Barnes, Killer, Toady and Mr. Toad, Amigo, Nemo and Pepe the Flea. As she grows up, she loses communication with some of these characters. However, she understands her family's speech better as the series progresses.
• Buster Baxter (voiced by Daniel Brochu; Jonathan Morris 2002-2012, 2000 redub, under-credited as Conway Bruce) is Arthur's best friend. He is a white rabbit who wears a turquoise long-sleeve polo shirt and jeans. He has asthma, is obsessed with aliens, loves telling jokes, is an amateur detective, and plays the tuba. He loves eating, practices gardening, and keeps expired food in his room and school desk. He is an only child whose parents divorced when he was younger. He created and celebrates a no-frills holiday called "Baxter Day" with his mother. His father travels the world as a pilot and has a spin-off series, "Postcards from Buster". Buster is also a procrastinator, often preferring to have fun rather than study; one such instance nearly led to him flunking third grade before cramming at the last minute. He's based on Marc Brown's best friend when he was younger.
• Francine Alice Frensky (voiced by Jodie Lynn Resther) is a tomboyish and sporty monkey who has short brown hair clipped with two yellow barrettes on both sides and usually wears blue jeans and a maroon sweater. She enjoys playing sports, playing the drums, and horseback riding. Her family is Jewish and is seen observing Yom Kippur and Hanukkah and attending a cousin's Bar Mitzvah in some episodes. Francine's best friend is Muffy, with both sharing the same middle name. In earlier seasons, she picked on Arthur, such as when he got glasses and his baby tooth would not come out, although later she is good friends with Arthur. She has an older sister named Catherine.
• Mary Alice "Muffy" Crosswire (voiced by Melissa Altro) is a monkey girl who usually has long red hair, which she usually wears in two braids adorned with purple bows that usually match her purple and white dress. She is one of two children born to Ed Crosswire, the owner of the used car dealership Crosswire Motors and his wife, Millicent Crosswire, the other being her older brother, Chip. Muffy is the quintessential daddy's girl, with Ed believing that his daughter can do no wrong and constantly buying expensive, trendy items such as cell phones and designer clothing. Because of her upbringing, Muffy sometimes shows herself to be rude and arrogant, and having lived in a mansion and waited on by servants her entire life, she has no sense of what it means to be lower or middle class. She is best friends with Francine Frensky, despite the two having similar strong-willed personalities. Often, Francine will rein Muffy in when her rudeness becomes unacceptable. She is seen with buck teeth in early episodes, though this was soon dropped.
• Alan "Brain" Powers (voiced by Luke Reid 1996–1999; Steven Crowder 2000–2001; Alex Hood 2002–2005; Bernadette Windsor 2002–2012 Paul-Stuart Brown 2004–2007; James Buckholder 2006; Lyle O'Donohue 2008–2012; Siam Yu 2012–2014; Max Friedman Cole 2014–2018; Evan Blaylock 2019–2022) is a bear boy of Senegalese descent who celebrates Kwanzaa. He usually wears a grey sweater. He is highly academic, has an A average and is well educated in many subjects, especially science and math. His classmates call him "Brain" or (when referring to him in third-person) "The Brain." His family owns an ice cream parlor, where his classmates frequently visit after school and on weekends. He was held back in kindergarten for crying and being afraid of swimming but can be seen swimming in some episodes.
• Shelley "Binky" Barnes (voiced by Bruce Dinsmore) is a yellow bulldog boy who usually wears an orange shirt, blue jeans and brown shoes. He is in the third grade for a second time after failing third grade and having to retake it. He is a member of the Tough Customers, which are a group of bullies, but has a soft side and is one of Arthur's friends. He plays the clarinet, catches butterflies and enjoys ballet. In "Binky Goes Nuts," it is revealed that he has a severe allergy to peanuts. Binky has an adopted baby sister from China named Mei-Lin. Despite being a bully, he is close with Arthur and his friends, he loves art, and in the episode "Binky Barnes, Art Expert," he tries to help Arthur and Buster. In the episode "Big Horns George," he compliments George's guitar by saying, "Woah, nice guitar! Can I see?" After giving the guitar back to George, he likes the chord George plays. Despite not being good at school, in "Binky's A Game," he reads his assigned book and receives an A on the test.
• Sue Ellen Armstrong (voiced by Patricia Rodriguez, or "Rodrigues" in early credits, 1996–2003; Jessica Kardos, 2004–2022) is a third-grader cat girl at Arthur's school, Lakewood Elementary. She officially moved to Elwood City in the winter of her third-grade school year (but has appeared in Mr. Marco's second-grade class). Her father is a diplomat, so her family has lived in various spots around the world. Unlike Emily, Tommy and Timmy, she traveled with her parents. She is very close to nature and becomes a vegetarian in Season 16. She is also deeply interested in world culture and is skilled in martial arts. She practices karate (taekwondo in earlier seasons) and plays the saxophone. Sue Ellen was born as an only child and kept in touch with her brother-like pen pal, Tenzin Wangdu, in Tibet. She is usually depicted wearing a teal "T-shirt dress," a cream vest with red buttons, red high-top shoes with a lime green "slouch" socks, and curly orange hair bound up in "messy-buns" by lime green scrunchies.
• Fern Walters (voiced by Holly Gauthier-Frankel) is a light brown dog girl and one of Arthur's classmates. She enjoys reading poetry and novels (especially "Sherlock Holmes" and "Frankenstein's Monster") and is particularly interested in gothic and horror themes. She has written many poems and stories of her own, holds group poetry readings at the library and is an amateur detective. Fern is usually a timid and nervous girl. She usually wears a purple long-sleeved blouse with yellow collars and cuffs, yellow pants, and a red ribbon on her head. Her close friend is George, as they both have similar personalities and sometimes act like detectives.
• George Lundgren (George "Nordgren" before season 11, voiced by Mitchell Rothpan 1996–2002, Bob Marshall 2002–2012, Evan Smirnow 2003, Samantha Reynolds 2008–2010, Eleanor Noble 2004–2007; 2010–2022) is a moose boy of Norwegian and Swedish descent, and wears an orange shirt with khaki pants and green sneakers. It is revealed in season 6 that he has dyslexia. He is very clumsy but can build items such as marionettes and constantly wins the school's contests. He is also timid and introverted, but as the series goes on, it shows that the others generally accept George. Finally, in Season 20, he is appointed as Lakewood Elementary's hall monitor.
• Prunella Deegan (voiced by Tamar Kozlov) is a poodle girl. In 2011, PBS said that she was a rat, but in 2013, Marc Brown confirmed that she is a poodle. She is interested in yoga, fortune telling, and paranormal phenomena. She loves Henry Skreever (based on Harry Potter) and has studied Braille. One issue Prunella struggled with is hoarding, outlined in the episode "Prunella the Packrat." She is a fourth grader who usually wears a blue dress with a white collar and a purple bow in her hair.
• Tommy Tibble and Timmy Tibble are identical twin bear brothers who are four years old and routinely exasperate others with their destructive antics. For example, Tommy wears a red scarf, and Timmy wears a blue scarf. They stay with their grandmother. Their parents work overseas and travel the world, giving them souvenirs and gifts. The twins torment D.W. Occasionally, they manipulate her into doing silly and unusual things that only get her into trouble even though D.W. had acknowledged many times that they always lie.
  • Tommy: voice actor is Jonathan Koensgen (1996–2002), Aaron Grunfeld (2002–2003), Tyler Brody-Stein (2004–2005), Madison Danielle (2006), Ryan Tilson (2006–2007), Jake Roseman (2008–2010), Jake Sim (2010–2016), Devan Cohen (2016–2022), Benjamin Hum (2019)
  • Timmy: voice actor is Ricky Mabe (1996–2000), Samuel Holden (2001–2005), Max Henry Wolf (2006), Tyler Brody-Stein (2006–2007), Chris Lortie (2008–2010), Dakota Goyo (2010–2012), Jacob Ewaniuk (2012–2016), Samuel Faraci (2016–2022), Matthew Mucci (2019)
• Emily Leduc (voiced by Vanessa Lengies Season 1–7 1996–2002, Sally Taylor-Isherwood 2003–2022) is a white rabbit girl with blonde hair, wearing a pink dress before season 6, and a blue dress since season 6. She is D.W.'s best friend in preschool. She is an expert in gymnastics and is knowledgeable in French culture. She has a French nanny named Marie Hélène.
• Maria Pappas (voiced by Stacey DePass, credited as Stacey Depasse) is a rabbit girl in Mr. Ratburn's class. Her clothing usually consists of a striped shirt with a blue dress. Her hair is brown. Maria's original character design included glasses. Maria participated in many clubs and activities but was never the center of attention. She appears in many episodes in the background, except for "Francine Goes To War," in which Francine insulted her, and her breakout episode, "Maria Speaks," which reveals that she talks with a stutter when she is chosen to be the reporter for the school's news program. Her best friend is Jenna Morgan.
• Alex Davidson (voiced by Riley Moreau) is a gray rabbit boy usually wearing a tan collared sweater, long brown jeans, and blue and white sneakers. In the episode Buster's Dino Dilemma, Alex wore a white shirt that had purple on it, purple shorts with green on it, long green socks, and red and white sneakers as an example.
• Jenna Morgan (voiced by Brigid Tierney) is one of Arthur's classmates. She is a gray cat girl who usually wears a pink dress with yellow buttons. She is lactose intolerant, plays badminton, helps coach soccer, and received an "Athlete of the Year" award from Michelle Kwan. Jenna is rather shy, and in "Jenna's Bedtime Blues," it is revealed that she dislikes being the center of attention and dreaded an invitation to Muffy's slumber party due to her fear of children discovering that she had nocturnal enuresis.
• Ladonna Compson (voiced by Krystal Meadows) is Bud's sister who first appeared in season 16, in the episode "Based on a True Story." She is a new student at Lakewood Elementary. Ladonna is a rabbit girl with a brownish-tan complexion who speaks with a dominant southern accent, and is native to New Orleans, Louisiana. Ladonna and her family end up moving to Oregon when her father Rufus is transferred there with the Corps of Engineers in "When Duty Calls." After said episode, however, she still appeared in episodes that were prequels to that one.

Other recurring children

• Adil Akyuz (voiced by Aaron Grunfeld) is a brown bear and Arthur's Turkish pen pal, who was introduced in "Dear Adil."
• Alberto Molina is a teenage boy who is one of Arthur's neighbors. He is a dark brown cat. He and his family were first introduced during season six, following the departure of Mr. Sipple. Alberto and his family hail from Ecuador. He practices kendo in his spare time and is very good at golf. In a continuous storyline throughout the entire Season 14, his soccer ball, lost by Francine, makes a long journey around the world and can be spotted as it appears in every episode. He was voiced by Johnny Griffin in "Follow the Bouncing Ball," Benjamen Israel in "The Long Road Home," and was voiced most recently by Daniel DeSanto.
• Alouysious Zimmerplotz is a kid in D.W.'s preschool class who has trouble writing his long name. He is a cat with yellow square glasses and a white shirt with a red jacket.
• Billy Bittles and Bobby Bittles are two vegetarian fraternal twins designed as bear cubs in the preschool class with D.W. Read. They appeared in Season 3.
• Bud Tucker Compson (voiced by Julie Lemieux) is Ladonna's younger brother, who also first appeared in "Based on a True Story." He is a rabbit with a light brown complexion who usually wears black rain boots, blue jeans, a lime T-shirt, a blue vest, and a red hat. He has an imaginary friend named Rapty, who everyone else sees as his beloved stuffed T-Rex. Bud is assertive, rugged, and not afraid of the Tibble Twins. He attends the same preschool as D.W. Read.
• Carl Gould (voiced by Dwayne Hill 2009–2010, Dylan Hoerner 2010–2016) is a cream rabbit with brown hair and blue glasses. His favorite color is blue. He has been diagnosed with Asperger syndrome, and his best friend is George Lundgren. He plays the accordion, flies kites, and is highly knowledgeable in locomotives (to the point where he can create detailed drawings of them from memory), lions, and space. He prefers to drink "apple juice from a box, not a bottle," to quote him.
• Catherine Frensky (voiced by Patricia Rodriguez 1997–2002, Alexina Cowan 2003–2012, Robyn Thaler Hickey 2012–2022) is Francine's older sister. She is in high school. Catherine is outgoing and skilled at horseback riding. She occasionally babysits for the Reads. She is embarrassed to tell people her father is a sanitation worker and likes to read teen magazines. She usually wears a white-sleeved jean jacket with a white oversized sweater/sweatshirt with black leggings, red slouchy socks, black and white shoes, and always wears her hair with bangs and a ponytail with a scrunchie.
• Cheikh (pronounced "Shake") (voiced by Thamela Mpumlwana) is Brain's cousin from Senegal who moves to Elwood City in the episode "In My Africa" and begins attending D.W.'s preschool. He and his parents become American citizens via naturalization in the episode "Citizen Cheikh."
• Chip Crosswire (voiced by Cory Doran) is Muffy's older brother, who is a college student at Tallahassee Tech, a fictional school. He was first shown in Muffy's family portrait in the book "Arthur Goes to Camp, " published in 1982. His name was first subtly revealed in "Arthur's Perfect Christmas" (there were separate Christmas stockings for Chip and Muffy side by side in their fireplace), but was later directly mentioned in the episode "Phony Fern." He wears a blue v-neck college sweater and a white turtleneck underneath. His first appearance was in "Matchmaker, Matchbreaker," where he comes home from college, where Muffy and Francine introduce him to Francine's sister Catherine.
• Cousin Cora is Arthur, D.W., and Kate's bratty cousin who appears in "D.W. Thinks Big." She acts like a brat when alone with D.W. but acts like a nice girl when adults are around. Her bratty nature is later exposed at their Aunt Lucy's wedding.
• Monique "Mo" (voiced by Melissa Pirrera) is Arthur, D.W., and Kate's oldest cousin, whom Arthur remembers when she had been awful to him in the past reunions and tried to avoid her until it is revealed that Mo isn't as bad as Arthur thought. She, like Arthur, plays the piano and says that Arthur is her favorite relative. Mo is the daughter of Loretta and has a younger athletic brother close to Arthur's age and an even younger sister close to D.W.'s age.
• Cousin Ricky is Mo's brother and Bud and Loretta's son. He is very athletic and somewhat bossy. His skin color changes in each episode he appears in.
• Cousin Ryder is Arthur's age and lives on the family farm in Ohio. While he and Arthur used to be close, they discover in "The Rhythm and Roots of Arthur" that they are pretty different and come to terms with their differences. Laurie is Ryder's baby sister. Cousin Miles grew up in Cleveland, but he has spent so many years living and working on the Read family farm that he has become a part of the family. He is the chief llama breeder on the farm.
• Isabella is a student at Mighty Mountain School who is a local chess master. She is known for tapping her fingernails during matches, which earned her the nickname "Los Dedos" (Spanish for "The Fingers"). At first, she has somewhat of a snobby personality as she is seen calling Brain an amateur after beating him in a game of chess on numerous occasions.
• James MacDonald (voiced by Robert Naylor 2003, Jesse Camacho 2004–2006, Nicholas Wheeler-Hughes 2007–2009, London Angelis 2010, John Flemming 2012–2014, Christian Distefano 2014–2022) (not to be confused with James MacDonald the sound effects artist) is a white rabbit that wears glasses. He is usually shy and quiet. He is in Ms. Morgan's class at preschool. He has an older sister named Molly MacDonald.
• Molly MacDonald (voiced by Maggie Castle) is close friends with Binky. She is a white rabbit and a senior member of the Tough Customers. She became a bully herself after being bullied in preschool, which she later avoided after discovering she was imitated by her younger brother James. She is good at giving advice but dislikes that everybody comes to her for it. She became friends with Arthur and D.W. and is an effective babysitter for the Tibble Twins. Molly has long maroon hair that mainly covers her eyes and often wears sleeveless shirts. She appears to be a stereotypical "punk kid" of the 2000s.
• Slink (voiced by Michael Yarmush) is a 4th grader rabbit. He is part of the Tough Customers. In his first episode in 1997, he convinced Buster to be "cool" by doing bad things. Decades later, in 2018's "Slink's Special Talent," he was revealed to be a good paper delivery boy.
• Rattles (voiced by Scott Beaudin) is another member of the Tough Customers. Rattles have been a Tough Customer member since the first season. His species is somewhat of a mystery; he appeared as a grey cat in the earliest seasons, then was made a dog in Season 8, and then was given rounded ears, like a bear, in Season 18. He wears a backward baseball hat, black leather jacket, green T-shirt, blue jeans, and high tops. He speaks with a Northern New Jersey accent. It was revealed in "Arthur Unravels" that he has an affinity for knitting. He is also skilled at playing chess.
• Lori appeared in the episode "When Duty Calls." She is an eight-year-old rabbit living next door to Ladonna at her new home in Oregon. Not much else is known about her.
• Lydia Fox (voiced by Barbara Mamabolo) is a physically disabled fox who helps Brain get over his temporary reliance on a wheelchair in "The Wheel Deal." Through her tutoring, he learns how to play basketball in a wheelchair and almost wins a charity game of free throws (though Lydia winds up taking over for the last few shots). Lydia was the winning entry of a children's contest to design a new character, sent in by Connor Gordon from Savage, Minnesota. In season 14, the voice actor credits gave Lydia the last name Gordon, but season 19 reverted her name to Lydia Fox. Lydia reappears in the season 19 episode "Little Miss Meanie" and the Season 21 episode "The Princess Problem."
• Marina Datillo (voiced by Helena Evangeliou) is a white rabbit in the 4th grade who attends Mighty Mountain Elementary School. She is blind, and she befriends Prunella after she inadvertently ordered a Braille copy of a "Henry Skreever" book and let her borrow it. Like Prunella, she is a big fan of "Henry Skreever."
• Mei Lin Barnes (voiced by Carrie Finlay) is Binky's baby sister, a bear, who was adopted from China. She is also Baby Kate's friend.
• Rubella Deegan (voiced by Eramelinda Boquer) is Prunella's older sister. She is very spiritual and practices psychic and paranormal phenomena. She is typically depicted as mystical and speaks dramatically, often chiding Prunella.
• Sally MacGill is Arthur's babysitter in "Crushed." She is a 16-year-old bear hired by Arthur's parents. Arthur developed a crush on her because of her skill in video games. However, Arthur was heartbroken when he found out she had a boyfriend.
• Tenzin was originally a child in poverty living in Tibet that Sue Ellen sent letters to for a while. He helped fill a void that Sue Ellen felt because Sue Ellen is an only child and doesn't have much in common with her friends. As a result, Sue Ellen mistakenly called him her "Little Brother." Later, he moved to Dharamsala, India, where he started to email Sue Ellen. They eventually met, revealing that Sue Ellen and Tenzin are the same age. He is a panda and originally had black fur. This was later retconned.
• Vicita Molina (voiced by Alyson Wener) is the Read family's new neighbor. Her age is "three and seven eighths," and, as a result, D.W. believes herself to be a role model. Vicita and her family are from Ecuador, and moved to Elwood City in Season 6, replacing Mr. Sipple.
• W.D. (full name is Wilhelmina Dagmar Merkles) (voiced by Raphael Cohen-Demers) is a tomboy counterpart to D.W. She is a bear. She has an imaginary friend Maxine. Her parents, Herman and Ursa, are great friends with The Reads; Meanwhile, W.D. and D.W. do not get along as much. Later, they develop a friendship despite their clashing personalities.

Adults

Arthur's family

• David Leonard Read (voiced by Bruce Dinsmore) is Arthur, D.W., and Baby Kate's father and husband of Jane. His mother is Grandma Thora, and he has three sisters: Loretta, who is older, Bonnie, who is younger, and Minnie, who lives in France. Mr. Read runs a catering business from home and is frequently shown garnishing trays of "hors d'œuvre" either in the family kitchen or in a custom-designed workshop behind the garage. He delivers his food in a dedicated commercial vehicle. Many of his recipes are questionable at first glance, and Arthur and D.W. often refuse to eat them, but at times they genuinely appreciate his cooking. He usually wears a white sweater with blue accents and khaki pants and sometimes has an apron and chef's hat on. His paternal family is originally from Ohio and still owns a llama breeding farm there, where David spent his summers as a boy. He has the same voice as Rudolph, the Red-Nosed Reindeer from The Secret World of Santa Claus.
• Jane Read (voiced by Sonja Ball) is Arthur, D.W., and Baby Kate's mother and wife of David. She has a younger sister, Lucy, an older sister, Jessica, and an older brother, Fred. Her father is Grandpa Dave. Mrs. Read is a work-at-home tax accountant. She has short, shaggy brown hair and wears a pink sweater, a white collared shirt, and blue jeans. In the books, she generally wears different clothes. She is from the Pittsburgh area and knew Fred Rogers as a child.
• Grandma Thora Read (voiced by Joanna Noyes) Grandma Thora is Arthur, D.W., Mo, Ricky, George, and Kate's paternal grandmother. "The Rhythm and Roots of Arthur" mentions that she spent summers at the Read family farm in Ohio when she was a girl. Grandma Thora is a columnist. In a flashback in "Clarissa is Cracked," Thora had three brothers. Grandma Thora is David, Loretta & Bonnie's mother. It is revealed in "April 9th" that she had gotten in a car accident (but was not hurt) when David was Arthur's age. Grandma Thora is based on Marc Brown's grandmother Thora, who encouraged him by saving his childhood drawings in a bottom drawer..
• Thora's mother is David Read's maternal grandmother, Arthur, D.W., Mo, Ricky, George, and Kate's paternal great-grandmother. She is seen as a young woman in "Clarissa is Cracked" and as an elderly grandmother in "Arthur's Cousin Catastrophe," where she wins the egg and spoon race.
• Grandpa Dave (voiced by A.J. Henderson) is Arthur, D.W., Cora, and Kate's maternal grandfather and the father of Fred, Jessica, Jane, and Lucy. He lives on the family farm in the country, which has been in the family for over 150 years. In "Grandpa Dave's Memory Album," he is revealed to be in the early stages of Alzheimer's disease.
• Uncle Bud and Aunt Loretta are Arthur, D.W., and Kate's paternal aunt and uncle. They are the parents of Monique, Ricky, and an unnamed daughter.
• Uncle Sean and Aunt Bonnie are Arthur, D.W., and Kate's paternal aunt and uncle; they are mother and father of George.
• Uncle Fred is Arthur, D.W., and Kate's maternal uncle and Jane, Jessica, and Lucy's brother. He is known throughout the family to be very clumsy. Fred has a Golden Retriever named Rory, who is awkward like him.
• Aunt Jessica and Uncle Richard are the maternal aunt and uncle of Arthur, D.W., and Kate; and the parents of Cousin Cora. They appear in "D.W. Thinks Big" during Aunt Lucy's wedding. Jessica also spoils her daughter Cora and takes her side even when she's wrong.
• Aunt Lucy is Arthur, D.W., and Kate's aunt. She appears in the episode "D.W. Thinks Big," where she is married, and D.W. saves her wedding ring. She is an aardvark with blonde hair. In the episodes "Go to Your Room, D.W.," "D.W.'s Perfect Wish," "D.W. Unties the Knot," and "Grandpa Dave's Memory Album," Arthur and D.W. mistakenly refer to Lucy as their cousin instead of their aunt.
• Additional Read Family Members In "The Rhythm and Roots of Arthur," the family celebrates the 85th birthday of Theodore Read (known as Theo), who is the brother of Grandma Thora's father. Everyone considers him to be the family patriarch. His long-deceased sister was named Dora Winifred and was D.W.'s namesake. Theo lives on the family farm in rural Ohio, along with Chrissy, the mother of Ryder and Laurie. An "'Uncle John," serving in the military overseas but who earlier lived on the family farm, is mentioned. In the same episode, the farm is visited by Cousin Jimmy and Cousin Lorraine, as well as by Minnie, who is D.W. and Arthur's aunt. She has a sophisticated look with embroidered pants, suits, loafers, cat-eye eyeglasses, and a bob with severe bangs. She is a vegetarian and does not like the Read family's farm, where she spent some time as a girl.

Other recurring adults

• Mr. Armstrong (Tony Robinow) is Sue Ellen's father, a retired diplomat. His job has forced him to move all across the world. However, he and his family enjoy the travel opportunities that come with it.
• Mrs. Armstrong is Sue Ellen's mother; She is a homemaker with a penchant for exotic clothes. She enjoys making clay pottery and sculptures.
• Bailey Carson Belvedere III (voiced by Bruce Dinsmore) is Muffy's chauffeur and sometimes the Crosswire Family's butler. He also has a notable talent for creating kinetic art. He follows Muffy's orders without question, to the extent of narrating a T.V. show during a power overload by using the limo's T.V. and phone. Another example is when he is ordered to drive the limo in a pretty dangerous fashion and whenever he has to carry several bags of luggage. He has received the harshest instruction to tow Muffy while on a bicycle. In the episode "The Butler Did What?" It was revealed that he played the trumpet, went to the same elementary school as Mr. Ratburn, where the two played in the school band, and is a jazz fan. He was initially called James. The name Bailey is based on the "Arthur" show director Greg Bailey. He is a grey bloodhound in a dark grey suit.
• Becky is an aardvark and is a Meadowcroak camp counselor and librarian.
• Ed Billings is the neighbor of Grandpa Dave's. He always offers to help Dave around his aging farm, but Dave is too proud to accept it until his grandchildren show him the value of accepting help from others, to which Dave asks Ed what he knows about tractor engines.
• Bubby (voiced by Joan Rivers) is Francine and Catherine's maternal grandmother who was first seen in "Arthur's Perfect Christmas." She later dies in the season 25 episode, "Listen Up," due to Joan Rivers' death in 2014.
• Mr. Barnes (John Moore; Peter Cugno) is Binky's father. He is revealed to work in a copy shop in the game "Arthur's 2nd Grade".
• Mrs. Barnes (Jane Wheeler; Liz MacRae) is Binky's mother, a nurse. She is protective of her son, especially in "Binky Goes Nuts."
• Bitzi Lynne Baxter (voiced by Ellen David) is Buster's mom, who is divorced. She is the editor-in-chief of the "Elwood City Times." In early episodes, she was over-protective of Buster and a frantic character but has settled down a bit in later seasons. (In the early "Arthur" books, she had blonde hair, although the last books and T.V. show depicted her with auburn hair.) The episode "Fright Night" reveals that she always had the surname Baxter before she married Buster's dad.
• Bo Baxter is Buster's father, who is divorced. He is a pilot. Buster flies with him around the United States in the spin-off "Postcards from Buster" series. In "Postcards from Buster," he is shown with short brown hair and glasses. However, his physical appearance has changed several times. Early appearances were partially concealed by various methods, such as reading a newspaper, Buster covering his eyes while on his shoulders, or Bo meeting him dressed as Santa Claus.
• Buster's Grandmother is Buster's maternal grandmother. Seen briefly in "Arthur Cleans Up," "Buster Makes the Grade," and the Postcards from Buster episode "Among the Hmong."
• Miss Blank is a past substitute teacher of Mr. Ratburn's class. She was the class' favorite substitute teacher because she never showed up, and the class had to be taught by Miss Sweetwater, who let them do coloring and gave them snacks.
• Coach Bumpus is a gym coach from earlier episodes. He is a rabbit. He often argues with Coach Grimsled over petty things like the last line of "The Itsy Bitsy Spider."
• Mrs. Bofini is a past substitute teacher in Mr. Ratburn's class. The class disliked her because she chewed with her mouth open in front of the class.
• Ms. Bryan is the Lakewood Elementary School Art teacher.
• Mrs. Cardigan is Arthur's former piano teacher who eventually retired and suggested he take lessons from Dr. Fugue later. She, like Miss Sweetwater and Mrs. Fink, offered each student cookies for having a wonderful lesson.
• Mrs. Grouse is one of Arthur and D.W.'s babysitters who always make them do dances.
• Edward Edsel "Ed" Crosswire (voiced by A.J. Henderson) is a very wealthy man who is Muffy and Chip's father and the owner of a large car dealership called "Crosswire Motors." He is an obese, stereotypical fat cat, who almost always wears a suit and a tie. It was revealed that he never attended college; rather he received an honorary degree from Ivy University after his donation of a library. He is also the current coach of Lakewood's soccer team. He was first shown in Muffy's family portrait in the book "Arthur Goes to Camp" that was published in 1982 and wasn't shown again until the first season of the cartoon show, where his appearance changed drastically.
• Millicent Crosswire (voiced by Jennifer Seguin) is Muffy and Chip's aristocratic mother. She also enjoys going to operas, as well as attending and hosting fancy parties. She was first shown in Muffy's family portrait in the book "Arthur Goes to Camp" that was published in 1982 and wasn't shown again until the first season of the cartoon show, where her appearance changed drastically.
• Cisely Compson is Ladonna and Bud's mother. According to Ladonna, she played in a band until she was 25, but got so broke she had to sell her trumpet, but then a soldier (who would one day be her husband) bought it back for her. She made Ladonna wear the snow hat her Aunt Bo gave her in "Based on a True Story".
• Mrs. Datillo is Marina's sighted mother. She was first seen in her daughter's second appearance in the Season 7 episode "Prunella Sees the Light".
• Wanda Deegan is Rubella and Prunella's mother. She enjoys yoga.
• Ms. Featherfoffer is a journalist that once babysat for Arthur. She was among the meanest of his babysitters, who told him it was bedtime during the day.
• Flossie is a hairdresser who owns and runs the Salon de Beauté, where Muffy gets her hair done. She also did Francine's hair in "Francine's Bad Hair Day".
• Mr. Elkin is a past substitute teacher of Mr. Ratburn's class. He was troublesome because his large antlers would accidentally knock students out of their seats.
• Mrs. Fink is one of the third grade teachers at Lakewood Elementary School. She is a teacher like Miss Sweetwater that does fun things with her class in contrast to Mr. Ratburn's hard work.
• Nurse Flynn works at Lakewood Elementary.
• Oliver Frensky (Mark Camacho) is Catherine and Francine's dad, who works as a sanitation engineer for the local city dump. He states he was formerly a volunteer firefighter. He coaches the Lakewood baseball team. He is very good-humored and is at times very childlike.
• Laverne Frensky (Jane Woods) is Catherine and Francine's mother.
• Grandpa Frensky is Oliver Frensky's father and Catherine and Francine's grandfather that owned an unnamed "hamburger castle" with unique hamburgers that is still open in the Background Blues episode. It is the show's version of White Castle. He also mentions Vingo Frensky, a barber for Abraham Lincoln in the show.
• Dr. Frederique Fugue is Arthur's current piano teacher, after Mrs. Cardigan retired. He later filled in for Ms. Krasny to take Mr. Ratburn's class to Crown City (the show's version of New York City) for a singing chorus field trip. He was a chorister as a child and later sung with the Whiffenpoofs, implying he attended Yale University. He is an extremely strict teacher and "fires" many of his students. However, he shows a softer side during the Crown City trip, openly encouraging his students to have fun with their singing. He also has a pet cat named Für Elise.
• Ted Glass is the Lakewood Elementary Crossing Guard. In his first appearance in "Arthur vs. the Very Mean Crossing Guard" he tried to fool Arthur and Brain into thinking there was a new $10 fee to cross the street and they believe him, becoming scared after he threatens to send goons to collect the money after they wait too long to pay up. After being told off by Grandma Thora he lets Arthur and Brain in on his joke and they join along in the fun.
• Coach Grimsled (Jeniffer Seguin) is a 4th grade gym coach at Lakewood. She has various debates with Coach Bumpus.
• Mrs. Gutter is one of Arthur's past babysitters. Arthur disliked her because she would play golf in the house.
• Harry Mills works at Bitzi's newspaper as a sports writer. Bitzi started dating him for a couple of seasons, but then broke off because she wanted more time to pursue other interests. Despite the break-up, he remained good friends with Buster and his mother as if nothing had happened.
• Francis Haney (voiced by Walter Massey in 1996–2014 before his death) is the lovable yet absentminded principal of Arthur's school. Like George, he has dyslexia. He also seems to have bad luck: something goes wrong almost everywhere he goes. A running gag in early episodes was a random item falling on his head, usually unintentionally caused by another character, such as Francine throwing a baseball way off course in "Arthur Makes the Team" and Loretta flipping the burgers too high in "Arthur's Cousin Catastrophe". In the Season 20 episode "The Hallway Minotaur", he was revealed to have moved away to Tanzania to build a school.
• Mr. Higgins is an Elwood City mail carrier.
• Dr. Iris is a cat and eye doctor who suggested that Arthur needed glasses in the first episode "Arthur's Eyes".
• Mr. Kone (voiced by Marc Graue) is the owner of an ice cream factory appearing in "Arthur's Missing Pal". He helps Pal escape from the ice cream factory, while also avoiding two ferocious dogs named Sugar and Spice.
• Ms. Krasny is the Lakewood Elementary School Music teacher. Her last name is named after Marc Brown's wife's maiden name.
• Fritz Langley is the caretaker of the Elwood City Community Garden who sometimes suffers from arthritis in his hands while working. He eventually moves to the retirement community.
• Mr. Leduc is Emily's father who is only seen during "Emily Swallows a Horse". and "The Good, the Bad, and the Binky". In the former episode, he is in bed, and his head is turned away, hiding his face. In a later episode, it is revealed that unlike his daughter and wife who are rabbits, he is a monkey. Emily is seen with Marie-Helene more than her parents which shows that they do not have much time for her.
• Mrs. Leduc is Emily's mother, who looks very different from her daughter. She makes many brief appearances, and in "Emily Swallows a Horse", she is seen in a gown, adorning herself which shows that she enjoys formal events. She is also seen in "The Good, the Bad, and the Binky".
• Neal Lundgren is the father of George Lundgren who is a carpenter running his own private wood repair shop in his garage and also teaches a shop class that his son sometimes attends.
• Mrs. Lundgren is George's mother who is seen much less than her husband; in fact she was only seen and heard in the episode "Kids are from Earth, Parents are from Pluto" and a brief appearance in the episode "April 9".
• Leah MacGrady (Sara MacGrady before season 13) is in charge of the cafeteria at Lakewood Elementary school. She is full of unconventional wisdom, and is Grandma Thora's bingo buddy. She commonly wears a pink shirt and white pants. She, like Prunella, enjoys fortune telling. In "The Great MacGrady", Mrs. MacGrady was diagnosed with cancer, but she has since continued to work at Lakewood, suggesting that she ultimately recovered from cancer. She was also a member of the band U Stink in the movie "It's Only Rock' N' Roll", a clip of which is seen while Francine writes a letter asking for advice to help her cope with MacGrady having cancer.
• Mr. Marco is Arthur's second grade teacher. He is often seen during the series, but Arthur was only in his class through flashbacks. He was a moose in the books, but in the show he is an aardvark just like Arthur. He is slightly stern, has zero tolerance for cheating, and is friends with Mr. Ratburn.
• Marie-Helene is Emily's French nanny, who takes care of Emily more than her parents and teaches her some French words.
• Herman Merkles (Andrew Sabiston) is a bear and is W.D.'s father. He is friends with David read who go canoe fishing together.
• Ursa Merkles (Tracey Hoyt) is a bear and is W.D.'s mother. She is friends with Jane Read, who helped her with tax papers. Ursa performs biology and geology research for fun.
• Ramon Molina is Arthur's new Ecuadorian neighbor, who moves in Mr. Sipple's old house with his family. He is revealed to own and run an Ecuadorian cuisine restaurant.
• Mrs. Molina (voiced by Dawn Ford) is the wife of Ramon Molina, and mother of Vicita and Alberto. In "Dancing Fools", she taught a children's dance class.
• Carl Manino is the longtime owner of the Sugar Bowl.
• Mr. Morgan is Jenna's father who was seen and heard from in the episode "Jenna's Bedtime Blues".
• Mrs. Morgan is Jenna's mother who very briefly appears in "Muffy's New Best Friend" and "Elwood City Turns 100", she helped to make the costumes for the play using her sewing machine; it appears that she has a talent in sewing.
• Ms. Morgan is D.W.'s preschool teacher, and a gymnastics instructor. She is a bear, an indication that she is not related to Jenna's family, who are all cats.
• Mr. Morris is the Lakewood Elementary School janitor, who moved to Roswell, New Mexico to live with his daughter after breaking his leg during the Lakewood fire on "April 9". He is seen in the Postcards from Buster episode "Alien Adventure", where Buster visits New Mexico. Although he moved away, he is seen in the background of several episodes post "April 9". Like Buster, he has asthma.
• Mrs. Pariso: Francine's next door neighbor, who is very good at horseback riding and also won prizes at Wimbledon. She appeared in the episode "Francine Goes to War" and an episode of "Postcards From Buster". She banged on Francine's wall when she first moved into their apartment building, which made Francine think she was a spirit who scares others to death, starting a brief rivalry; luckily, the two became good friends in the end when they both discover they like soda and horseback riding. Francine later explained that the reason Mrs. Pariso was mean was because she was lonely. She kind of ignored Francine and Prunella when they disturbed her. When Buster called her a witch, she didn't seem to mind it (unlike Francine) and told a story about how she had met a warlock once.
• Patrick Ratburn (Marcel Jeanin) is Mr. Ratburn's husband that he marries in the episode "Mr. Ratburn & the Special Someone". He sells chocolate, including a particular chocolate that he refers to as a "Frieda Kahlo", at Patrick's Chocolates in Elwood City.
• Signore Pelato is a clown barber who owns and runs the Signore Pelato Barber Shop in "D.W., Queen of the Comeback". In the same episode, he cuts D.W.'s hair too short, causing the Tibble Twins to nickname her "Dennis".
• Pickles is a local circus clown who does gigs in Elwood City including birthday parties and Elwood City's annual Downtown Day.
• Mr. Powers (voiced by Terrence Scammell) is Brain's father, who appears to have average intelligence compared to The Brain. Not much is known about him.
• Mrs. Powers (voiced by Susan Glover) is Brain's mother, who owns and runs the ice cream shop. She was originally shown with a brown complexion and brown hair but she is now seen with a light complexion and blonde cream-colored hair.
• Mr. Pryce-Jones is an extremely strict teacher at Glenbrook Academy, where knowledge (and classwork) is unlimited. He is Mr. Ratburn's favorite teacher. Mr. Pryce-Jones is "irreplaceable" as he hadn't retired by the time Arthur and his classmates attended the Medieval Fair; Pryce-Jones was teaching a class of seemingly unbeatable rival students. Mr. Haney was impressed by Glenbrook's performance and hired Pryce-Jones to be a tutor for his niece and nephew.
• Nigel Charles Ratburn (voiced by Arthur Holden) (Emil Ratburn in Season 1) is Arthur's third and fourth grade teacher. He attended Glenbrook where his passion for learning and teaching was guided by his teacher, Mr. Pryce-Jones. Various running gags involving Mr. Ratburn are of his strictness and love of homework, food, and dessert (especially cake). He usually drives a small red convertible but also bought a minivan and canoe online. He is a fanatic of the series "Spooky-Poo!", a spoof of "Scooby-Doo". In the Season 22 episode "Mr. Ratburn and the Special Someone", Mr. Ratburn is revealed to be gay when he marries his same-sex partner, Patrick, in a wedding attended by his students. The episode, which also had lesbian actress Jane Lynch voice Mr. Ratburn's older sister and wedding planner Patty, was praised by LGBTQ groups as helping to normalize same-sex marriage, but attracted some controversy from conservative groups for displaying a same-sex wedding on a children's T.V. show. It is of note that Mr. Ratburn did not marry Arthur. The episode was withheld from airing by Alabama Public Television (APT) and Arkansas Educational Television Network (AETN) as it showcased same-sex marriage.
• Rodentia Ratburn is Mr. Ratburn's sister, who once filled in for Mr. Ratburn when he had laryngitis. The students initially liked the simplicity of her methods, but they proved way too childish for their age and were actually happy to have Mr. Ratburn back. In the later episode "Desk Wars", it would seem that she gave birth to a child, as Mr. Ratburn left for a phone call in which his sister told him he was an uncle.
• Mrs. Robertson is the Lakewood Elementary School Kindergarten teacher who is now retired. Her retirement diorama risked exposing Brain's secret that he was held back in kindergarten.
• Mr. Sanders is the building superintendent who works for the apartment building where the Frensky family lives.
• Mrs. Shmigaedy is one of Arthur's old babysitters, a moose who made great cookies but was rather clumsy because of her large horns.
• Susy Sipple (Mark Camacho) is Arthur's next-door neighbor from Seasons 1–6, who enjoys grilling fish late at night and comes from a place where making faces on a bike means "bring me a cabbage". When he first appears, he was mowing his lawn and almost killed Toady Wartface. His name is revealed when D.W. learns to ride a bicycle. He moves out of the neighborhood in Season 6, and the Molinas move into his home.
• Dr. Sozio is a dentist that the Read family goes to. A gag is parents forbidding children to put their hands in his "mouth" (a plastic model displaying teeth). He is a bear and wears glasses.
• Miss Sweetwater: She is also a third grade teacher at Lakewood Elementary School. She does fun things with her students like singing songs (especially "I Like Fudge") on her guitar. In the early "Arthur" books, she was depicted as a cat, but the cartoon and later books depicted her as a rabbit.
• Mrs. Terracini is a grandmother to one of the children in D.W.'s Class. She is very old and can neither see nor remember names very well, as she called the "Tibble Twins" the "Toggle Twins".
• Mrs. Tibble is the grandmother of Tommy and Timmy Tibble. (In early Arthur books, Mrs. Tibble is a human, however many newer books and the show have her as a bear.) She lives with the twins and has gray hair tied in a high bun.
• Miss Tingley is Principal Haney's secretary and the assistant principal of Lakewood Elementary School. One time she was afraid of Miss Sweetwater's singing and Mr. Haney's sawing-in-half magic trick. She is an excellent public speaker compared to Mr. Haney, and she has had to rephrase and conclude his long, confusing speeches. She soon becomes the temporary principal in Season 20 after Mr. Haney resigned.
• Mrs. Tremello is a past substitute teacher of Mr. Ratburn's class. She was disliked by the class because she mumbled everything she said.
• Paige Turner (Katie Hutchinson) Paige is Ms. Turner's first name, pun is intended as she is in charge of the Elwood City Library. She is friendly, polite, and calm to her patrons and associates. A running gag is a widespread fear of her by the patrons due to their worries of failure and responsibility. Her hair color has changed from dark brown to light brown. She wears glasses and also has numerous watches. She is a rabbit.
• Mr. Walters is the father of Fern who is seen much less than his wife but was finally first seen in the episode "Phony Fern", plus in the episode "Fernlets by Fern". He is a brown dog in a blue jacket. He taught Fern about computers.
• Doria Walters is Fern's mother. She works for a real estate company. Her hair is noticeably a different style than Fern's, which hides Doria's ears. She has an outgoing personality and is very confident and encouraging to her daughter, Fern (who would prefer it if she wasn't).
• Mrs. Wood is Perky's owner. Her grouchy dog, Perky (aka "Jaws"), is Pal's mother.

Guest stars

• Art Garfunkel appears in animation as a moose in two "Arthur" episodes (January 4, 1999 – January 31, 2006 on PBS Kids) and it's February 1, 2006 on PBS Kids Go! He first appears in the episode "The Ballad of Buster Baxter", and then later appears in "Elwood City Turns 100!" as one of the guests that Muffy invites to the play.
• Arthur Ganson appears in the episode "Muffy's Art Attack".
• The Backstreet Boys (Nick Carter, Howie Dorough, Brian Littrell, A.J. McLean, and Kevin Richardson) appear in the movie Arthur, It's Only Rock 'N' Roll.
• Click and Clack, The Tappet Brothers (Tom and Ray Magliozzi) appear in the episode "Pick a Car, Any Car", where Arthur calls them about the family car to save it from the junkyard.
• Matt Damon appears in the episode "The Making of Arthur" as the host of a show "Postcards from You" (inspired by the "Postcards from You" segment that has been the mid-show feature on "Arthur" since Season 11 and the feature on the second season of "Postcards from Buster").
• Édgar Rentería also appears in "The Curse of the Grebes" also playing a Grebe, being Bateria.
• Frank Gehry appears in the episode "Castles in the Sky", and helps the gang create a new tree house, although they don't know he is Frank Gehry until he gives them a signed photo of the Guggenheim Museum in Bilbao.
• Fred Rogers appears on the episode "Arthur Meets Mr. Rogers". Fred was an old friend of Jane Read. He visits Arthur's house and Arthur is embarrassed because he and his friends think that "Mister Rogers' Neighborhood" is a "baby show". When Mr. Rogers comes for a visit to Arthur's class, they gain a new appreciation for the show.
• Idina Menzel appears on the episode "Shelter from the Storm", as Dr. Paula, a therapist who consoles Brain when he starts to have anxiety attacks after a hurricane hit Elwood City.
• Jack Prelutsky appears on the episode "I'm a Poet", as the judge of a poetry contest. At the end of the contest, he can't decide who's the winner, so he says "I hate contests. You "all" win".
• Johnny Damon also appears in "The Curse of the Grebes", also playing a member of the Elwood City Grebes as Playmon.
• John Lewis appears in the episode "Arthur Takes a Stand" when he speaks at Lakewood Elementary. He knew Mrs. MacGrady, who participated in the March on Washington for Jobs and Freedom with him, and joins a sit-in led by Arthur.
• Joshua Redman appears in the episode "My Music Rules" as Francine's mother's second-cousin-twice-removed, who they call "Uncle Josh". He gets invited by Arthur and Francine.
• Koko Taylor appears in the episode "Big Horns George", and is The Brain's favorite blues musician.
• Drawn as a pale, slightly aged rabbit, Lance Armstrong appears in "Room to Ride", to encourage Binky Barnes on his bike lane campaign. He reappears in "The Great MacGrady", to help Francine feel less afraid about Mrs. MacGrady having cancer.
• Larry King appears in live action during the "And Now a Word From Us Kids" section of the episode "Elwood City Turns 100!" and interviews the gang.
• Michelle Kwan appears in the episode "The Good Sport", as the hostess of the Athlete of the Year Award at Lakewood Elementary. It is also said that she graduated from Lakewood Elementary in that series.
• Mike Fincke appears in the episode "Buster Spaces Out", when Buster, Arthur, Francine, Muffy, George and Carl are trying to launch a rocket. He speaks of his ordeal during the first EVA of Expedition 9 in 2004.
• Mike Timlin appears in the episode "The Curse of the Grebes", playing a member of the Elwood City Grebes, being Winlin.
• Ming Tsai of "Simply Ming" appears in the episode "What's Cooking?" as a judge for Arthur's school in a kid cooking contest.
• Neil Gaiman appears in the episode "Falafelosophy", where he offers Sue Ellen advice about the graphic novel she is writing after meeting her at a falafel stand.
• Rodney Gilfry appears in the episode "Lights, Camera... Opera!" as he has a role in the Carmen opera that Muffy and Ed Crosswire see.
• R. L. Stine as Buster's uncle Bob Baxter.
• Taj Mahal also appears in the episode "Big Horns George" with Koko Taylor.
• Yo-Yo Ma appears in the episode "My Music Rules" with Joshua Redman. He is the musician that D.W. invites to the library.
• Alex Trebek appears as a fictional version of himself, Alex Lebek, as the host of the game show "Riddle Quest," on which Arthur is a contestant.

Imaginary friends

• Maxine is D.W.'s imaginary friend. She has an exotic purple hair style. She appears as an elephant.
• Nadine Flumberghast (Hayley Reynolds) is D.W.'s imaginary friend. She portrays D.W.'s conscience and usually appears when D.W. feels guilty, scared, or angry. Both D.W. and Nadine are aware that Nadine is imaginary. However, Kate, Mei-Lin, animals, and other characters' imaginary friends can see and communicate with her. One episode shows D.W. with her when she's much older, while another shows that D.W. does not need Nadine as much as she used to. She appears as a brownish-yellow squirrel. She has long platinum white blonde hair styled exotically in three pigtails and small buck teeth. She can create imaginary items and they can appear/disappear with magic. Her last name was revealed to be "Flumberghast" in the episode, "Read and Flumberghast".
• Rapty is Bud's imaginary friend. He is a big green dinosaur. He is actually a toy, although Bud imagines him as real. In "D.W. & Bud's Higher Purpose," it is shown that he can communicate and talk to Nadine.
• Trini is Vicita's imaginary friend. She is a very intelligent and truthful fairy, and, in one episode, where the imaginary friends team up, she is the unelected leader of the group.
• Uncle Wormy is the Tibble Twins' imaginary friend. He is a giant slimy worm with one eye (red) and wears a belt with the letters "U.W." on it, standing for his own name, Uncle Wormy.

Animals and pets

• Amigo (Robert Brewster) is the Molinas' pet bulldog. Like Pal, Amigo has been shown to speak in some episodes. "Amigo" means "friend" (or "pal") in Spanish.
• Fur Elise is Dr. Frederique Fugue's pet cat from the Arthur episode, "D.W.'s Furry Freakout". Named after Für Elise by Beethoven.
• General Higgins is Ladonna's pet rat. He can do tricks, and is very smart for a rat.
• Killer (Melissa Pirrera) is a stray dog found on Grandma Thora's porch. She had been to the pound many times and was known for being vicious. It is unknown who her previous owner was, but her current owner is Grandma Thora. Pal and Amigo were once afraid of her because of her bite, but her reputation was saved when she rescued Nemo by barking at some firefighters on a rainy day. Killer is shown in the very early books as Grandma Thora's dog, but she was not introduced on the T.V. series until season 9.
• Mr. Toad is a stereotypical business investor who invested in "The Sock Market" as well as "The Lint Rush". Husband of Toady Wartface.
• Nemo (Greg Kramer) is Francine's tuxedo cat, also Pal's worst enemy. In the first episode he was shown in, however, they were friends. Arthur also disliked him at first, mistaking his playful antics for hostility due to his general dislike of cats. His facial features changed drastically after his debut. Before he was called "Nemo", he was called "Rose Petal" by Catherine, Francine's older sister. For some reason, even though Pal and Nemo were friends in "Francine and the Feline", they are enemies in every later episode except "Pet Projects".
• Pal Read (Simon Peacock, main speaking voice, from season 6 onwards, Michael Yarmush from season 1, Arthur Holden from season 3, Yvette Kaplan in "Arthur's Missing Pal", vocal effects by Frank Welker) is Arthur's pet puppy. He is a mixed breed of English Setter (from dad) and St. Bernard. D.W. often refers to him as "Arthur's crazy dog". In earlier episodes, he was easily excited and often destroyed the house, but Arthur was able to train him. He is revealed to be able to speak in some episodes, but other than Kate and most other animals, no one can understand him. When he does speak, he speaks properly with an English accent in an adult voice, despite being a puppy.
• Pepe (Rick Jones) is an Italian flea friend of Pal and Kate who tells stories. He is first introduced in "Flea to Be You and Me", and later reappears in "Mei Lin Takes a Stand" and "Around the World In 11 Minutes".
• Perky is Pal's mother. She appears in "Arthur's Pet Business". She was once infamous for harboring a grouchy attitude, which caused the mailman to nickname her "Jaws", but it might be because she was pregnant. Along with Pal, Perky had two other puppies.
• Pixel is the pet dog of Capri DiVapida.
• Rory is the pet dog of Uncle Fred in Arthur's Perfect Christmas.
• Sebastian Winkleplotz (voiced by Alan Cumming) is an award-winning poodle.
• Snowball is D.W.'s "pet" snowball that disappeared one day. D.W. got very upset over it and thinks that Arthur stole it. In a later episode, D.W. thinks that she found her snowball, but it once again is lost. It is revealed that the second snowball was actually a sno-cone without syrup flavoring on it that Arthur ordered for D.W. to end her complaining about the first one. Later, it is revealed in "All Will Be Revealed" episode that Nadine kept the snowball safe while aliens had accidentally taken a crochet ball.
• Spanky is D.W.'s pet parakeet. He died in "So Long, Spanky" and was buried in a grave. He is seen again in "I'd Rather Read it Myself" as a bald eagle in D.W.'s imagination.
• Sugar and Spice are two ferocious dogs and Mr. Kone's dogs that tried to kill Pal in "Arthur's Missing Pal".
• Toady Wartface is a toad formerly owned by D.W.; she was found near Spanky's grave and became D.W.'s pet, filling the void Spanky left. She is released afterwards. She later appears in "The Great Sock Mystery" and "The Great Lint Rush", revealing that she now lives in the Reads' yard and has since married Mr. Toad.
• Walter (Michael Caloz) is a deer that D.W. meets in the outdoors, D.W. wants to take Walter home but her parents tell her it's not allowed. Walter is also seen in other episodes when D.W. daydreams or imagines her perfect world.