Ryūzaburō Ōtomo (大友 龍三郎, Ōtomo Ryūzaburō, born May 18, 1952) is a freelance Japanese actor, voice actor and narrator who was formerly affiliated with Aoni Production, 81 Produce and the Tokyo Actor's Consumer's Cooperative Society.

Due to his deep voice, he often plays villainous characters like fellow voice actor Norio Wakamoto, either in children's programs such as Mahōjin Guru Guru (as Lord Giri), Myotismon from Digimon, Crocodile from One Piece, and Montana Jones (as Zero) or in villainous roles such as Yūsha Keisatsu J-Decker (as Jūsan Saejima) and Shadow the Hedgehog (as Black Doom). He has taken over ongoing roles for voice actors Shigezō Sasaoka, Eiji Kanie, Shinji Nakae, Daisuke Gōri and Hirotaka Suzuoki after their deaths. A number of his foreign film-dubbing roles are occupied by Tesshō Genda in different editions of those films.