The film stars Tom Cruise (who also co-produced) in the role of American soldier Nathan Algren, whose personal and emotional conflicts bring him into contact with samurai warriors in the wake of the Meiji Restoration in the Empire of Japan in 1876 and 1877. Other actors include Ken Watanabe, Shin Koyamada, Tony Goldwyn, Hiroyuki Sanada, Timothy Spall, and Billy Connolly. The film’s plot was inspired by the 1877 Satsuma Rebellion led by Saigō Takamori, and also on the stories of Jules Brunet, a French army captain who fought alongside Enomoto Takeaki in the earlier Boshin War and Frederick Townsend Ward, an American mercenary who helped Westernize the Chinese army by forming the Ever Victorious Army.

Tom Cruise as Captain Nathan Algren, a Civil War and Indian Wars veteran haunted by the massacre of Native American civilians at the Washita River. Algren was born in the British Empire but is a naturalized American. Following a dismissal from his job, he agrees to help the new Meiji Restoration government train its first Western-style conscript army for a hefty sum. During the army’s first battle he is captured by the samurai Katsumoto and taken to the village of Katsumoto’s son, where he soon becomes intrigued with the way of the samurai and decides to join them in their cause. His journal entries reveal his impressions about traditional Japanese culture, which almost immediately evolve to admiration.

Ken Watanabe as samurai Lord Moritsugu Katsumoto, a warrior-poet who was once Emperor Meiji’s most-trusted teacher. He is displeased with Mr. Omura’s bureaucratic reform policies, which leads him into organizing a revolt against the Imperial Army. Katsumoto is vaguely based on real-life samurai Saigō Takamori.

Shin Koyamada as Nobutada, Katsumoto’s son who is lord of the village that the Samurai are encamped in and befriends Algren. Katsumoto, the leader samurai, advises Nobutada to teach Algren in the Japanese way – Japanese culture and Japanese language. He is killed during Katsumoto’s escape.

Tony Goldwyn as Colonel Bagley, Capt. Algren’s commanding officer in the 7th Cavalry Regiment, who was to train the Imperial Army and a main antagonist. Algren despises Bagley for his role in the Washita River massacre of the Native Americans that Algren cannot get over. In a flashback, we see Bagley murdering children and women in the Indians camp. Bagley bears close resemblance to General Custer (whom Algren dubs “a murderer who fell in love with his own legend”). Bagley is killed by Algren in the final battle when Algren throws his sword into his chest.

Masato Harada as Omura, an industrialist and pro-reform politician who dislikes the old samurai and shogun related lifestyle and the primary antagonist of the film. He quickly imports westernization and modernization while making money for himself through his railroads. Coming from a merchant family that was like many repressed during the days of Samurai rule and cause for his extreme dislike for their nobility, he assumes a great deal of power during the Meiji Restoration and takes advantages of Meiji’s youth to become his chief advisor (wielding power similar to those of the Shoguns). His image is designed to evoke the image of Okubo Toshimichi, a leading reformer during the Meiji Restoration. Masato Harada noted that he was deeply interested in joining the film after witnessing the construction of Emperor Meiji’s conference room on sound stage 19 (where Humphrey Bogart had once acted) at Warner Brothers studios.

Shichinosuke Nakamura as Emperor Meiji. Credited with the implementation of the 1868 Meiji Restoration, the Emperor is eager to import Western ideas and practices to modernize and empower Japan to become a strong nation. His appearance bears a strong resemblance to Emperor Meiji during the 1860s rather than during the 1870s, when The Last Samurai takes place.

Hiroyuki Sanada as Ujio, one of the most dedicated, loyal and fierce samurai under Katsumoto. He teaches Algren the art of Samurai sword fighting, none too gently but eventually grows to respect him. He is one of the remaining samurai to die in the final charge in the last battle.

Timothy Spall as Simon Graham, a British interpreter for Captain Algren and his non-English speaking soldiers. Initially portrayed as a typical practical-minded Englishman, he later comes to understand the Samurai cause. This character is shown to have some resemblances also to the real-world Corfiote photographer Felice Beato.

Seizo Fukumoto as the Silent Samurai, an elderly man assigned to follow Algren (who later calls the samurai “Bob”) as he travels through the village. Ultimately, the Samurai saves Algren’s life (and speaking for the first and only time, “Algren-san!”) by taking a fatal bullet for him. He bears a marked resemblance to Kyuzo from Seven Samurai.

Koyuki as Taka, Katsumoto’s sister and the wife of the red-masked Samurai Hirotaro, whom Nathan Algren kills earlier.

Billy Connolly as Sergeant Zebulon Gant, an ex-soldier who served with and is loyal to Algren, talked him into coming to Japan. He, along with Algren, train the imperial army before confronting the samurai. He is later killed in the opening battle by Hirotaro (Taka’s husband).

Shun Sugata as Nakao, a tall jujutsu and naginata-skilled samurai, who takes part in Katsumoto’s rescue, and is later killed in the final battle.

Satoshi Nikaido as the Lieutenant, one of the first soldiers trained by Algren, who manages to escape from the battle where Algren is captured. He later reappears as Omura’s aide in the final confrontation; distressed at the slaughter of the remaining samurai, he defies Omura by ordering the guns to stop firing so that Katsumoto can die with honor.