Liliana Mumy is an American actress and voice artist known for her extensive work in animation, particularly for voicing characters in various animated series and films. She was born on April 16, 1994, in San Marcos, California, and began her career in the entertainment industry as a child actress in the early 2000s. She is the daughter of actor and musician Bill Mumy, which provided an early entry into acting, but she established her own career through numerous roles in both live-action and voice acting.

Mumy's introduction to voice acting came early with her work in English dubs of Japanese anime. A notable example is her role as the voice of Nonoko, the young daughter in the Yamada family, for the English-language version of the Studio Ghibli film My Neighbors the Yamadas, which was released in the United States in 2005. She also lent her voice to another acclaimed Studio Ghibli film, providing the voice for Madge in the English dub of Howl's Moving Castle. These roles are part of a broader career in voice acting that distinguishes her from performers who focus solely on on-screen work.

Beyond her work in anime dubs, Mumy has built a substantial career voicing characters for numerous American animated television series. She is known for providing the voice of Mertle Edmonds, the rival of the title character, in the Lilo & Stitch franchise, including the television series and several direct-to-video films. She voiced the character Twinkle in the children's series Higglytown Heroes from 2004 to 2008. For Cartoon Network, she was the voice of Panini, the obsessed apprentice, in the series Chowder from 2007 to 2010. A significant recurring role includes voicing Roxy for 45 episodes of the Nickelodeon revival of Winx Club between 2012 and 2015.

Mumy has also been part of recurring collaborations and long-running projects. She voices Beth Tezuka in the animated web series Bravest Warriors, a role she has played since 2012. Her most prominent and enduring voice role is as Leni Loud, one of the ten sisters in the main cast of the popular Nickelodeon series The Loud House. She began voicing Leni in 2016 and has continued the role in the series, its spin-off The Casagrandes, and feature-length films like The Loud House Movie in 2021 and No Time to Spy: A Loud House Movie in 2024. This body of work, spanning live-action television and film as well as a diverse range of voice acting roles across major networks and studios, represents her notable achievements in the entertainment industry.