Shirō Saitō is a Japanese actor and voice actor born August 31, 1956, in Sakata, Yamagata, Japan. He is affiliated with the theatre company and talent agency Bungakuza and has been active in the industry since 1981.

Saitō has built an extensive career spanning both anime and dubbed foreign productions. In anime, he is known for a wide range of character roles. One of his most recognized performances is providing the voice for Yoruichi Shihōin in her cat form in the long-running series Bleach. His other notable anime roles include Bao in Black Lagoon, Sorbet in Dragon Ball Z: Resurrection F and Dragon Ball Super, Bluenote Stinger in Fairy Tail, Gansaku Nanbu in Megalobox and its sequel Megalobox 2: Nomad, and Nishida in Sword Art Online. His filmography also includes roles in major animated films such as Princess Mononoke, Spirited Away, and My Oni Girl.

In 2024, Saitō voiced the character Ranbō in the web anime series Garouden: The Way of the Lone Wolf. His recent and ongoing work demonstrates a continued presence in the industry, with roles in series like Dandadan, Blue Miburo, and The Seven Deadly Sins: Four Knights of the Apocalypse.

Beyond anime, Saitō is prolific in the field of voice-over dubbing for foreign films and television series. He is well-known as the consistent Japanese voice of Rubeus Hagrid, originally played by Robbie Coltrane, in the Harry Potter film series. He has also dubbed the voice of Biff Tannen from the Back to the Future trilogy and provided Japanese voices for numerous other actors in films like Armageddon, Mad Max: Fury Road, and the Aquaman movies. His dubbing work extends to animation as well, where he has voiced characters such as Jake the Dog in Adventure Time, Frozone in The Incredibles, and Vilgax in the Ben 10 series.