Hiro - The main character of Digimon World. He was brought to the Digital World by Jijimon to save File Island from being destroyed by evil Digimon, who were losing their memory and turning evil. He had many different partners over the course of the game but he started out with the partner Agumon or Gabumon.
Analogman - The main human villain. He believes that Digimon should all be slaves to humankind. His Digimon partner is Machinedramon.
Akira - The main character of Digimon World 2. He had many different partners over the course of the game but he started out with the partner Patamon (canon to the story, but in-game Akira has the choice of becoming a Black Swords, Gold Hawks, or Blue Falcons tamer). Later on, he also befriends a MetalGreymon in the BIOS Domain.
Joy-Joy - Partners: Monzaemon, Deramon, Starmon, Ninjamon, Raremon. Best friend of Bertran's, and always around him, trying to calm him down when he gets frustrated with Akira, whom she seems to be fairly kind with, although gets mad at him when he defeats her digimon in the Colloseum.
Kim - Partners: Wizardmon, Seadramon, Akatorimon, Ogremon. Infiltrates the city and steals the Generator Parts from the Tamer's Club. She is thought to be a villain, but after Akira defeats her digimon in Modem Domain he discovers that she was only borrowing the Generator Parts for her sister to invent something new for the Digital World. In the ending, it seems she becomes attracted to Akira. Although unknown if it is canon to the story, the in-game picture of her has her wearing goggles which symbolizes leadership in the Digimon series, along with Akira, which could mean she does have a future with him.
Ben Oldman - Partners: Centarumon, MetalMamemon, Meramon. Former leader of the Blue Falcons, went into hiding after the "Blood Knights Incident". Held the secret to reaching File Island.
Techna-Donna - The sister of Kim, who gives Akira the Power Radar after he realizes that the standard radar isn't powerful enough for certain domains, specifically the Giga Domain.
Professor Piyotte - Partners: Yanmamon, Syakomon, Ikkakumon. Expert in Digimon DNA, knows a great deal about digimon and DNA digivolving. Akira comes to the professor to ask him where the Archive Ship is.
Mark Shultz - Partners: Saberdramon, Gururumon, ShimaUnimon. Gold Hawks Tamer, and tells Akira about a MetalGreymon in the BIOS Domain whom Akira eventually befriends, using the Toy Plane he gives Akira.
Brian Wiseman - Partners: Garudamon, AeroVeedramon, Mammothmon. A high ranking Gold Hawks tamer, who seems to have a romantic interest in Esmeralda. He battles Akira in the Colosseum.
Cecilia - Partners: Jijimon, Magnadramon, MarineAngemon. Leader of the Blue Falcons, and also the head trainer for students becoming Digimon Tamers. Akira joins her team after his last mission in becoming a Tamer is complete (canon to the story, but in-game Akira has the choice of joining the Black Swords or Gold Hawks).
Debbie - Partners: Palmon, MoriShellmon, JungleMojyamon, Togemon, 3 Mamemon. A Blue Falcons tamer, usually hangs around in the Tamer's Club, where she has her dancing Palmon that a Black Swords Tamer eventually falls in love with when Debbie leaves.
Chris Connor - Partners: Bakemon, Woodmon, Soulmon, Phantomon, Myotismon, Megadramon. A black Black Swords tamer, who gives Akira a Toy Plane in the Digimon Trading Center, a very powerful gift that can help befriend any type of Digimon the best. Later on, he goes to File Island and becomes confused by Gekomon in the Data Domain and mistakes Akira for an enemy.
Junior (Atsushi (アツシ?) in the Japanese version) - The main character of Digimon World 3.
Teddy (Takumi (タクミ?) in the Japanese version) - One of Junior's friends. He apparently idolizes a famous hacker known as Lucky Mouse.
Ivy (Minori (ミノリ?) in the Japanese version) - One of Junior's friends. Her Digimon Online alias is Kail (Kite (カイト,Kaito?) in the Japanese version). According to Junior, she hadn't shown any interest in Digimon before. Later, it turns out she wanted to find her brother, Kurt.
Kurt - His Digimon Online alias is Lucky Mouse. He helps out Junior in some situations, disguised as a Numemon. He is later revealed to be Ivy/Kail's brother, shortly before he is turned into an Oinkmon by the AoA.
Protagonist - The character chosen by the player as a boy or girl. He/she decides to discover the truth behind the rumors of 'computer monsters' which begins his/her journey in the Digital World. Cares about Digimon and does them many different favors throughout the game. Starts with either Koromon, Tsunomon, or Tanemon.
ClavisAngemon - The King of the Digital World. He strives to create peace between humans and Digimon.
Pagumon - First appears to the protagonist as a BlackAgumon who hates humans and tamed Digimon. He digivolves into DarkTyrannomon, but is defeated by Machinedramon. One of the Protagonist's quests is to help raise Pagumon, who slowly becomes attached to him/her. It was revealed that he was once an Antylamon who was abandoned by his tamer during a battle with Kimeramon.
Kain - The main human antagonist of the game and the protagonist's rival. He only cares about having the strongest Digimon and will abandon anyone who he sees as weak. For a short time, he masquerades as the leader of the Bad Tamers and is the mastermind behind the capture of the Four Beasts. He is used by Alphamon to awaken Chronomon. He has a MegaKabuterimon, which he forces to become GranKuwagamon, at the start of the game, but in his guise as BT Leader, he has a MarineAngemon.
Alphamon - The main Digimon antagonist. A powerful Digimon who despises humans. He begins plotting behind ClavisAngemon's back under the alias "Unknown-D".
Tomomi - At first, she was Kain's partner, always hanging out with him and sharing his twisted ideas. She has a change of heart after Kain ditches her, leaving at the mercy of his berzerk GranKuwagamon. She becomes an ally of the protagonist afterwards. While she was with Kain, she had a Dragomon.
Yuji - A high ranking tamer who aids the protagonist throughout the game. He makes his appearance when he saves the protagonist from Kain and Tomomi. One of his partners is Cyberdramon.
Koh is the main character of Digimon World: Dawn, and is a rising tamer in the Light Fang organization. He is partnered with Coronamon, and is rivals with Sayo. It is possible to pick a different name or gender for him when starting the game.
Chief Glare is the leader of Light Fang, and is partnered with Ophanimon. In Dawn, he begins acting strangely after a certain point, and is encountered at the Access Glacier during a quest which the player has to defeat him and Ophanimon in order to snap him back to his senses. In Dusk, he is under the control of the Chrono Core and you will fight him before you get to Chaos Brain where you would face the final boss of the game.
Litton is a gold tamer.
Gideon is a silver tamer.
Raigo is a silver tamer.
Gaoh is a bronze tamer.
Lyla is a bronze tamer.
Pulsa is a normal tamer that seems to be best friends with Koh. He is partnered with Sandiramon.
Komachi is a normal tamer. She is partnered with Gomamon.
Kenpa is a normal tamer. She's a very shy and kind girl that just wants to help in any way she can. She follows Cheetah and Tonpei when they went to Login Mountain, but gets separated from them and you find her at the near start of the dungeon. She is partnered with Biyomon.
Tonpei is a normal tamer. He was one of the guys that ran off with Cheetah and got stuck in battling Aquilamon until you save them. He is partnered with Gabumon.
Cheetah is a normal tamer. He appears to be a stubborn guy, but can get scared easily when chances look bleak. You would have to search him in a quest because he wasn't chosen to investigate the Digiworld after SunshineCity was attacked by Grimmon and decided to run off with Tonpei and Kenpo. At Login Mountain, you would have to fight an Aquilamon that looks like it was affected by the virus to save them, but after you do, he still shouted that he could handle it himself, even though he was cowering in fear before the battle. He is partnered with Patamon.