Millennium Actress (千年女優; Sennen Joyu) is a 2001 animated film by Japanese director Satoshi Kon.

The narrative style is complicated and interwoven in the style of "play within a play": the film itself is about a director, Tachibana, who is working on a documentary about a famous actress, Chiyoko. Chiyoko has grown old and has withdrawn from public life, but Tachibana slowly draws her out. The story of Chiyoko's life, from teenage schoolgirl to middle-aged superstar, gradually unfolds, as told through flashbacks interspersed with segments taken from her long history of films. Chiyoko's life spans the tumultuous period surrounding World War II, while her characters in movies span a time period from Sengoku period through a futuristic spaceage.

Chiyoko's story is ultimately one of faith and longing, while the device of segments from earlier movies allows the setting, characters, and perhaps most importantly the visual style of the film to change suddenly in interesting ways. Some of the scenes are reminiscent of Japanese Ukiyo-e woodblock prints, while others evoke Akira Kurosawa movies (particularly Throne of Blood). Director Kon has acknowledged the influence of Throne of Blood, but says that for the most part there are not specific references in his segments. Instead he drew on a vague general impression of the history of Japanese filmmaking and visual art for his different styles and stories; Kon insists that historical film was actually not a subject he had much familiarity with before he made Millennium Actress. He studied the settings and costumes carefully, however, and learned a lot in the making of the film, such as the history of the kimono.

Another intriguing device in Millennium Actress is the anachronistic appearance of Tachibana in a number of Chiyoko's film flashbacks. This could be considered an acknowledgement of the fact that Chiyoko is not merely remembering her past, but recounting it to Tachibana and his comic relief cameraman. Their appearance in Chiyoko's retellings implies the participation of the listener inherent in any public retelling. It also acknowledges Tachibana's deep familiarity with Chiyoko's work.

The character of Chiyoko herself is somewhat reminiscent of Setsuko Hara a famed Japanese movie star of the 1940s, 1950s, and 1960s who likewise withdrew suddenly from public life. Kon has recognized this influence in an interview.

Millennium Actress received the Grand Prize in the Japan Agency of Cultural Affairs Media Arts Festival. It was also promoted by its studio as a contender for the 2003 Academy Award for Best Animated Feature, but it was not nominated.