Tom Cruise
Known for his ability to immerse himself into a role on and off the screen, Cruise approached the role of Algren in his typical Stanislavskian manner. Drawing on the character of Ron Kovic, the injured veteran whom he had played in Born on the Fourth of July, Cruise also submerged himself in Samurai culture, including the correct way to brandish a sword, and he also developed an interest in the history of the Samurai / Shogun culture. He also admitted that learning the Japanese language was difficult for him because of his dyslexia.
Cruise was nominated for a Golden Globe award n the Best Actor category for his portrayal of Captain Algren.
Ken Watanabe
Katsumoto is based on real-life Samurai Saigo Takamori, one of the three great nobles of the Meiji Restoration. He even gave the film its title as he is also referred to as the "last true samurai."
Probably best known for his performances in Christopher Nolan's Batman Begins and Inception, Watanabe is a highly decorated actor in his native Japan, winning two Japanese Academy Awards in the years following his portrayal of Katsumoto; he was also nominated for an Oscar in the Best Supporting Actor category for his performance in The Last Samurai.
Tony Goldwyn
Goldwyn comes from one of Hollywood's most royal of families, his grandfather, Samuel, considered one of the greatest directors in the history of film. Goldwn's Colonel Bagley is an interesting mix of service and remorselessness. Goldwyn has appeared in a surprising five movies with the word "last" in the title, ranging from The Last Tattoo in 1994 to The Last House on the Left almost two decades later.
Matsato Harada
The character of Omura is based on real-life progressive reformer and Westernizer Okubo Toshimichi, another of the Three Great Nobles who was credited with creating the birth of the modern Japan. Harada was extremely interested in joining the cast of the film after seeing the construction of the set for Emperor Meiji's conference room on sound stage 19, attracted to both the attention to detail on the set, and the fact that Humphrey Bogart had also acted there.
Timothy Spall
Spall's talent for portraying deliberately vague, overly practical and sometimes completely clueless Englishmen made him a perfect choice for the role of Simon Graham; he was Zwick's first (and admittedly only) choice, after having seen him in a succession of Mike Leigh collaborations. He is probably best known to younger audiences as Peter Pettigrew in the Harry Potter series.
Billy Connolly
The role of ex-soldier turned best friend Gant is somewhat of a dramatic departure for Connolly who is best known for both his dramatic comedy and stand-up comedy performances. Once called "the funniest man on earth" Connolly's career began in a fairly controversial way as a member of the irreverent comedy team behind Not The Nine O'Clock News, but later performances in straight roles, most notably as John Brown in the movie Mrs Brown, for which he received a BAFTA Award in the Best Supporting Actor category.
Shichinosuke Nakamura
Meiji is credited with the implementation of the Restoration in 1868, and was a strong advocate for Westernization which he believed would ultimately create in Japan a strong international nation. Nakamura was cast not just for his acting abilities but for the startling visual resemblance to the real-life Emperor Meiji, although he appears to be more like the Meiji from a decade prior to the events that occurred in The Last Samurai.
