Fiona is a hippopotamus born at the Cincinnati Zoo and Botanical Garden in Cincinnati, Ohio, United States, on January 24, 2017. The first Nile hippo imaged on ultrasound pre-natally and the first born at the zoo in 75 years, she was born prematurely and cared for with the assistance of the Cincinnati Children's Hospital.
Fiona's parents are Henry and Bibi. (Henry died at 36 in October 2017.) She is the first Nile hippo to be born at the Cincinnati Zoo in 75 years, and the first of the species to be scanned in the womb using ultrasound. She was born six weeks premature on January 24, 2017, with a birth weight of 29 pounds (13 kg); the recorded range of birth weights for the species at that time was 55–120 pounds (25–54 kg). She was unable to stand and required bottle feeding with milk from her mother, supplemented with infant formula. This was the first time a hippopotamus had been milked and the milk analyzed. The following month, while teething, she began refusing her bottle and became dehydrated; a catheter for the delivery of intravenous fluids was inserted with the assistance of members of the vascular access team at Cincinnati Children's Hospital. The preemie team had previously sent the zoo a care package for her.
Zoo staff named the baby hippo Fiona because her ears made them think of a Shrek heroine, and also because it means "fair". Fiona took her first steps on February 5, weighed 275 pounds (125 kg) by May 31, when she was introduced to the media, and by June had reached a normal weight of 317 pounds (144 kg); by the time she was six months old, she weighed over 375 pounds (170 kg), and in late August, 451 pounds (205 kg). On her first birthday, January 24, 2018, she weighed more than 655 pounds (297 kg). By December 26th, 2018, she weighed slightly over 1,000 pounds (450 kg). 
The Fiona Show was launched on Facebook in August 2017. Saving Fiona, a children's book about her written by the zoo's director, Thane Maynard, was published in June 2018. A video posted on social media by the zoo went viral, as did a couple's photographs of Fiona watching them get engaged in October 2017. In August 2018 a mural of Fiona was unveiled in downtown Cincinnati; Lucie Rice won the contest to design it.
Fiona appeared in Cincinnati Ballet's December 2018 production of Nutcracker, played by a 6 ft 4 in (193 cm) dancer, and "stole the show". Illustrator Richard Cowdrey has written two books about Fionna, including a Christmas book A Very Fiona Christmas.
- "Hospital saves baby hippo at US zoo". 2017-02-21. Retrieved 2019-10-12.
- Mallorie Sullivan (November 1, 2017) [October 31, 2017]. "Henry the hippo, dad of adorable Fiona, dies in Cincinnati". Cincinnati Enquirer – via USA Today.
- Shauna Steigerwald (January 24, 2017). "Premature hippo in critical care at Cincinnati Zoo". Cincinnati Enquirer – via WKYC (Cleveland).
- "Hospital saves dehydrated baby hippo at Cincinnati Zoo". BBC news. February 21, 2017.
- Shauna Steigerwald (February 5, 2017). "Cincinnati Zoo's premature hippo Fiona takes first steps". Cincinnati Enquirer – via USA Today.
- Rachel Syme (November 25, 2017). "Hooray for Fiona the Hippo, Our Bundle of Social-Media Joy". The New York Times.
- "Cincinnati Children's team gives Fiona life-saving IV". WCPO. February 20, 2017.
- Camila Domonoske (February 5, 2017). "Baby Hippo, Born Prematurely, Takes Her First Steps". The Two-Way (with video). NPR.
- The Cincinnati Zoo & Botanical Garden (September 19, 2017). "Baby Hippo Fiona - Episode 3 Bigger & Better". YouTube (video). Retrieved December 26, 2017.
- Shauna Steigerwald (May 31, 2017). "Fiona the hippo dazzles in front of the cameras". Cincinnati Enquirer – via USA Today.
- "How the world fell in love with Fiona the hippo". WLWT. June 22, 2017.
- Kevin Tidmarsh (July 24, 2017). "While Fighting The Odds, Fiona The Hippo Became A Social Media Star". Morning Edition. NPR.
- Ariel Scotti (August 29, 2017). "Fiona the Hippo starring in her own show". New York Daily News (with video).
- Jenna Amatulli (January 24, 2018). "Nothing Else Matters Today Because It's Fiona The Hippo's Birthday". Huffington Post.
- Jenna Amatulli (August 8, 2017). "Parents: Fiona The Baby Hippo Is Getting A Children's Book". Huffington Post.
- "New Fiona Book by Cincinnati Zoo Director Thane Maynard Hits Stores on June 19". Cincinnati Zoo. June 15, 2018.
- Fernando Alfonso III (October 24, 2017). "Couple has engagement photo photobombed by cute baby hippo". Houston Chronicle.
- Mallorie Sullivan (October 25, 2017). "Fiona the hippo gets the late-night treatment on Jimmy Fallon". Cincinnati Enquirer.
- Carol Motsinger (August 15, 2018) [August 14, 2018]. "Fiona the hippo now a part of the Cincinnati cityscape". Cincinnati Enquirer.
- Carol Motsinger (January 7, 2019). "Watch out, Cincinnati: There are some more hippos in town". Cincinnati Enquirer.
- David Lyman (December 14, 2018). "Review: Dancing hippo right at home in 2018 'Nutcracker'". Cincinnati Enquirer.
- "Fiona the Hippo spreads Christmas cheer in new book". TODAY.com. Retrieved 2019-12-16.
- Hippo Baby Fiona Updates, Cincinnati Zoo