A nameless ronin, or samurai with no master, enters a small village in feudal Japan where two rival businessmen are struggling for control of the local gambling trade. Taking the name Sanjuro Kuwabatake, the ronin convinces both silk merchant Tazaemon and sake merchant Tokuemon to hire him as a personal bodyguard, then artfully sets in motion a full-scale gang war between the two ambitious and unscrupulous men.
| Sanjuro Kuwabatake / The Samurai | Toshirō Mifune |
| Unosuke, gunfighter | Tatsuya Nakadai |
| Nui | Yōko Tsukasa |
| Orin | Isuzu Yamada |
| Inokichi | Daisuke Katō |
| Seibê - brothel operator | Seizaburō Kawazu |
| Tokuemon, sake brewer | Takashi Shimura |
| Yoichiro | Hiroshi Tachikawa |
| Kohei's Son | Yōsuke Natsuki |
| Gonji, Tavern Keeper | Eijirō Tōno |
| Tazaemon | Kamatari Fujiwara |
| Hansuke | Ikio Sawamura |
| The Cooper (Coffin-Maker) | Atsushi Watanabe |
| Homma, Instructor Who Skips Town | Susumu Fujita |
| Ushitora | Kyū Sazanka |
| Kuma | Kō Nishimura |
| Ronin Kobuhachi | Takeshi Katō |
| First Samurai | Ichirō Nakatani |
| First Foot Soldier | Sachio Sakai |
| Kame | Akira Tani |
| Kannuki the Giant | Namigoro Rashomon |
| Kohei | Yoshio Tsuchiya |
| Magotaro | Gen Shimizu |
| Roku - Samurai Whose Arm is Cut | Jerry Fujio |
| Matsukichi | Yutaka Sada |
| Kumosuke | Shin Ōtomo |
| Ushitora Follower | Shōichi Hirose |
| Yahachi | Hideyo Amamoto |
| Sukeju | Shōji Ōki |
| Second Samurai | Fuminori Ōhashi |
| Farmer | Hiroshi Kiyama |
| Traveler | Senkichi Ōmura |
| Farmer's Ex-wife | Noriko Honma |
| Seibei Follower | Ryusuke Nishio |
| Seibei Follower | Naoya Kusakawa |
| Seibei Follower | Nadao Kirino |
| Mitsuo Tsuda | |
| Ushitora Follower | Shinpei Takagi |
| Seibei Follower | Jun Ōtomo |
| Ushitora Follower | Akio Kusama |
| Ushitora Follower | Yasuzō Ogawa |
| Ushitora Follower | Hiroshi Takagi |
| Seibei Follower | Jun'ichirō Mukai |
| Takuzō Kumagai | |
| Second Foot Soldier | Ichirō Chiba |
| Ushitora Follower | Haruya Sakamoto |
| Seibei Follower | Rinsaku Ogata |
| Ushitora Follower | Takeo Ogushi |
| Woman at Seibei's House | Yoko Terui |
| Woman at Seibei's House | Hiromi Mineoka |
| Woman at Seibei's House | Michiko Kawa |
