Cassius Romero is a Brazilian voice actor, actor, and cartoonist, widely recognized for his extensive work dubbing anime and live-action series into Brazilian Portuguese. He was born in São Paulo, Brazil, on May 22, 1966.

Before establishing himself in voice acting, Romero had a distinct career in visual arts. He spent eight years illustrating album covers for Warner Music and also worked as a comic book artist, even publishing science fiction stories in the French edition of Heavy Metal magazine. His entry into voice acting began in 1992 at the Álamo dubbing studio in São Paulo, where he started with small roles after finding himself unemployed.

Romero is particularly well-known within the anime community for lending his voice to a wide array of characters. He has voiced several prominent roles, including Smoker in the franchise One Piece and its film One Piece Stampede, Sakonji Urokodaki in Demon Slayer: Kimetsu no Yaiba, Bercouli Synthesis One in Sword Art Online: Alicization, and Peyote Diaz in Shaman King. His filmography also includes characters such as Shingo Maezawa in Dragon Pilot: Hisone and Masotan, Rob in The Duke of Death and His Maid, Inugane in Back Street Girls: Gokudolls, Flail in Fire Force, Rigurd in That Time I Got Reincarnated as a Slime, and Sansão in Ultraman: The Adventure Begins.

His career, however, extends far beyond these titles. He is celebrated for iconic dubbing roles from earlier decades, such as Aoshi Shinomori in Samurai X (Rurouni Kenshin), Tuxedo Mask in Sailor Moon, and Supreme Lord Kaioshin in Dragon Ball Z and Dragon Ball Super. His versatility spans multiple genres, including voicing live-action characters like Negan from The Walking Dead and providing the Brazilian voice for actors such as Sylvester Stallone (in Rambo redubs) and Arnold Schwarzenegger (in The Terminator redubs). He has also voiced characters in Western animation, including Vinny in Family Guy and Hermes Conrad in the early seasons of Futurama. Throughout his career, Romero has become one of the most recognizable and respected voices in Brazilian dubbing.