Isabella Guarnieri, also known as Isa Guarnieri, is a Brazilian voice actress known for her work on the Portuguese dubs of various anime series. She has built a substantial career voicing a wide array of characters across numerous popular franchises. Among her most recognized roles are Nezuko Kamado in Demon Slayer: Kimetsu no Yaiba and Mio Kofune in Summer Time Rendering.

Guarnieri's filmography demonstrates her extensive work in the industry, with credits spanning multiple genres and series. She voices Himiko Toga in My Hero Academia, Yuzuriha Ogawa in Dr. Stone, and Priestess in Goblin Slayer. Her repertoire also includes characters in long-running and acclaimed series such as Attack on Titan, where she voices Hitch Dreyse, and One Piece, where she has played Marianne, also known as Miss Goldenweek, among others. She is also the voice of Holo in Spice and Wolf, Alice Sakayanagi in Classroom of the Elite, and Chain Sumeragi in Blood Blockade Battlefront.

Her work often involves reprising roles across multiple seasons and adaptations of a series, indicating recurring collaborations with the studios and direction teams responsible for the Brazilian Portuguese dubs of these anime. This is evident in her long-standing roles in franchises like Attack on Titan, My Hero Academia, and Dr. Stone, where she has voiced the same character across several installments. Her portrayal of Nezuko Kamado extends to the series' sequel, Demon Slayer: Kimetsu no Yaiba - The Movie: Mugen Train.

Notable achievements in her career include being part of the casts for some of the most globally popular anime of recent years. Her role as Nezuko in Demon Slayer, a cultural phenomenon, and as Himiko Toga in the long-running hit My Hero Academia, places her work in front of a vast international audience. Her casting in the Brazilian Portuguese dub of the critically acclaimed film your name. as Yotsuha Miyamizu further highlights her presence in significant anime productions. Through these performances, Isa Guarnieri has established herself as a prominent figure in Brazilian anime dubbing.