Rintarou Nishi is a seasoned Japanese voice actor, narrator, and stage actor, recognized for his rich, deep voice and his ability to portray a wide range of characters, particularly authoritative, tough, or villainous roles. He was born Kazuaki Kurita on July 15, 1965, in Osaka, Japan. His stage name, Rintarou Nishi, was given to him by a theater director early in his career.

Nishi's path to performance began in his youth, inspired by the actor Yuusaku Matsuda. He joined the Bungakuza Acting School in 1987 and later graduated from the Yen Acting Institute in 1988. His professional career started in theater when he joined the Yen Performing Group in 1991. His transition to voice acting was somewhat serendipitous, occurring after his agency provided him with a script for an anime role. Despite initial hesitation about acting using only his voice, he embraced the medium and has since built an extensive career in animation, video games, and dubbing. He is currently affiliated with the talent agency Office Osawa.

Throughout his career, Nishi has become a familiar presence in a multitude of popular anime series. He has taken on significant roles such as Jiguro in Moribito - Guardian of the Spirit, Baus in Beet the Vandel Buster Excellion, and Ryuichi Jinnai in Government Crime Investigation Agent Zaizen Jotaro. He is also known for his performances as Moblit Berner in Attack on Titan, Jason in Tokyo Ghoul, and Tetsuzaemon Iba in Bleach. In the long-running series One Piece, he voices the character Heracles. In the series ID: INVADED, he played the role of Matsuoka. He has also lent his voice to the healthy leader in the anime film adaptation of Chocolate Underground.

Nishi is particularly well-known for his work in The Seven Deadly Sins franchise. He voices both the narrator of the series and King Bartra Liones, a role he has reprised across multiple installments, including The Seven Deadly Sins: Imperial Wrath of The Gods and The Seven Deadly Sins: Cursed By Light. Beyond anime, he is a prolific voice actor in video games, with notable roles including Masaru Watase in the Yakuza series. He also has a strong presence in tokusatsu, having portrayed memorable villains like Shadam in Gosei Sentai Dairanger and Doukoku Chimatsuri in Samurai Sentai Shinkenger.

One of Nishi's most notable achievements is his work in dubbing foreign films and television series. He is the go-to Japanese voice for actor Vin Diesel, dubbing his performances in major film series such as xXx and The Chronicles of Riddick. His dubbing filmography is extensive and includes providing Japanese voices for a wide array of Hollywood actors in films like The Expendables 3, The Three Musketeers, and Mortdecai. His deep and resonant voice has made him a natural fit for action stars and authoritative figures in live-action dubbing.