Sidnei Dias is a Brazilian actor, voice actor, and dubbing director, born in Rio de Janeiro on February 20, 1963. He has an extensive career in dubbing, lending his voice to numerous live-action films and television series. In addition to his work as a voice actor, he has also directed dubbing projects.

Dias has a significant body of work in anime, providing the Portuguese voice for characters in a wide range of series and films. One of his notable roles is Albert d'Andrésy in the anime Lupin the 3rd Part 6. His other anime credits include the characters Gaston and Julius in Berserk: The Golden Age Arc - Memorial Edition, the Hospital Director in Baki, a conspirator in Dr. Stone: Stone Wars, a Minotaur in Dragon Goes House-Hunting, Yoshiken in Housing Complex C, a commander in ID-0, the principal in both seasons of Kono Oto Tomare!: Sounds of Life, a PLF Vice Commander in My Hero Academia, and Mimisenri in Yashahime: Princess Half-Demon - The Second Act. He has also participated in the Portuguese dubs of other major titles such as Appare-Ranman!, DEVILMAN crybaby, Fate/Apocrypha, Vinland Saga, and Violet Evergarden, and has voiced characters in films like Lu over the wall and Lupin III vs. Cat's Eye.