Ruby Barnhill is an English actress recognized for her voice work in English-language dubs of anime films. Her most prominent role in the medium is providing the voice for the title character in the Studio Ponoc film Mary and the Witch's Flower. Her career in voice acting is closely linked with this studio, as she has also been cast in a subsequent Ponoc production.

Barnhill's entry into voice acting for anime came through her involvement with Studio Ponoc's debut feature. Following her breakout live-action role as Sophie in Steven Spielberg's The BFG, she was cast as Mary Smith in the English dub of Mary and the Witch's Flower. The film, directed by former Studio Ghibli animator Hiromasa Yonebayashi, was released in 2017 and featured Barnhill in the lead role alongside esteemed actors such as Kate Winslet and Jim Broadbent. At the time of recording, Barnhill was close in age to her character, which contributed to an authentic performance. She has described the voiceover process as enjoyable and noted her personal appreciation for Studio Ghibli films, which influenced her connection to the project.

Her collaboration with Studio Ponoc continued, as she was confirmed to voice the character Aurora in the English dub of the studio's later film, The Imaginary, which was released in 2024. This recurring work with the same animation studio marks a significant through-line in her voice acting career. Beyond her work with Studio Ponoc, Barnhill has also lent her voice to other animated projects, such as the title role in the 2019 film Princess Emmy, further establishing her presence in the field of voice performance for family-oriented animation.