Cidalia Castro is a Brazilian singer, actress, and voice actor with a career that began in 1994, initially as a professional singer and composer. Her entry into voice acting occurred in 2002 when she was invited to dub the singing voice of the main character in the Disney series That's So Raven. This opportunity leveraged her musical background and set the foundation for a career that often merges her vocal and acting skills. Her work is primarily in Brazilian Portuguese dubs for a wide range of international productions.

As a voice actor, Castro is known for dubbing a variety of characters in both live-action and animated works. In live-action, she notably dubbed Emma Thompson in two prominent Disney films: as Mrs. Potts in the 2017 live-action adaptation of Beauty and the Beast, where she also performed the character's songs, and as the villainous Baronne von Hellman in Cruella. In animation, her extensive voice work includes characters such as Orizaba in Elena of Avalor, Nanpire in Vampirina, Thoebe in Ridley Jones: A Guardiã do Museu, and Edna in Arlo, o Menino Jacaré. In the Studio Ghibli animated film Earwig and the Witch, she voiced the role of Mãe da Earwig, the character who adopts the protagonist. Her work also extends to anime, with a credit for the character Sweet Pea in the long-running series One Piece.

Castro's career is marked by frequent collaborations within the Brazilian dubbing industry. She has worked extensively for major studios, including Universal Cinergia, and has been the musical director for dubs of productions from Disney, Nickelodeon, Paramount, and Netflix. A significant recurring professional relationship is with voice actor and studio founder Wendel Bezerra. In 2015, Bezerra invited her to become the musical director at his studio, UniDub, where she began directing episodes of SpongeBob SquarePants and series like ALVINNN!!! e os Esquilos. She has also collaborated with fellow musical theatre actor Fred Silveira on various projects.

Among her notable achievements, Castro was selected by Disney from approximately 300 candidates to sing the song "Espíritos Ancestrais" (Great Spirits) for the Brazilian Portuguese version of the 2003 film Brother Bear. Her work as a musical director has also received recognition; her direction on the films Parque dos Sonhos and Ugly Dolls in 2019 garnered praise from international producers. Beyond dubbing, her career is deeply rooted in music and theatre. She has released several solo albums, worked as a backing vocalist for renowned Brazilian artists like Tim Maia and Gilberto Gil, and performed in major musical theatre productions in Brazil, including O Fantasma da Ópera and A Noviça Rebelde.