Fiona Hardingham has provided voice work for the anime franchise Pokémon, specifically playing the role of the Arrival Video Narrator in the 2019 film Pokémon Detective Pikachu. Her performance in this project is sometimes credited simply as Additional Voice. This role represents her most direct connection to anime-style animation, as the Pokémon series is a prominent example of Japanese anime adapted for international audiences.

Beyond her work in the anime genre, Fiona Hardingham is a highly accomplished voice-over artist and award-winning audiobook narrator. She trained as an actor in London, earning a BA Honors at Middlesex University and studying at the Western Australian Academy of Performing Arts, before moving to Los Angeles in 2008. Her voice career spans animation, ADR, commercials, documentaries, video games, trailers, and film. Her animation credits include voicing Jacqui the French mouse in Disney's The Magic of the Glass Slipper, a short film created for the 100th-anniversary edition of Cinderella. She also performed lead roles in the SMOSH series Otaku Taco Truck and the feature film Monster Island.

In the realm of voice-over achievements, Hardingham has earned significant recognition. She has narrated over four hundred and thirty titles across various genres and has received twenty AudioFile Earphones Awards. She won the Audie Award for Best Middle-Grade Audiobook in 2021 for The Good Hawk by Joseph Elliott and the Audie Award for Best Fiction in 2022 for the full-cast narration of The Final Revival of Opal & Nev by Dawnie Walton. She also received an ALA Odyssey Honor for The Scorpio Races by Maggie Stiefvater. For three consecutive years, titles she narrated were included in the Young Adult Library Services Association's list of Top Amazing Audiobooks for Young Adults.

Additionally, Hardingham held a recurring role as the ongoing voice announcer for ESPN's Grantland and later Jalen & Jacoby, a position she maintained for over a decade.