I'm Going to Tell You a Secret is a 2005 American documentary film that follows singer Madonna on her 2004 Re-Invention World Tour. Directed by Jonas Åkerlund, the film premiered on MTV on October 21, 2005, and was released on DVD on June 20, 2006, by Warner Bros. Records. The documentary was originally called The Re-Invented Process, referencing the tour and the Steven Klein exhibition titled X-STaTIC Pro=CeSS. It starts with imagery from the exhibition and Madonna auditioning dancers for the tour, continues with her entourage travelling through different cities and performing, the singer's introspection on her life, her marriage, her religion, and her children, and ends with Madonna's visit to Israel in the midst of protests.

The documentary was inspired by Madonna's need to show her artistic side on the tour and her devotion towards the Jewish mysticism Kabbalah. Unlike her 1991 documentary Truth or Dare, which portrayed Hollywood glamour, I'm Going to Tell You a Secret clarified from its beginning that it was about the singer's personal views on life and spirituality. Like Truth or Dare, the performance scenes were shot in color, while the rest of the film was in black-and-white. Besides Madonna, her dancers and her tour entourage, Åkerlund also shot her family, her working process and her day-to-day life. Madonna and her then-husband Guy Ritchie's local pub in Mayfair, London was used for some sequences. The film features appearances from Madonna's father, stepmother and filmmaker Michael Moore.

Before releasing the documentary, Madonna invited a select group of friends and co-workers to watch a rough three-hour cut of the film at a local theater in Notting Hill. The film was trimmed after negative feedback regarding excessive details about Kabbalah. For the promotion and premiere of the film, Madonna appeared at Q&A sessions with the press and also gave a speech to film students at New York's Hunter College. Critical response to I'm Going to Tell You a Secret was mixed, with reviewers complimenting the live performances and the scenes involving her children and family, but criticizing the self-indulgent and perceived pretentious nature. I'm Going to Tell You a Secret was released in a two-disc format, a CD with 14 songs from the show and a DVD with the documentary film. It received a positive response from critics but was a moderate success commercially.