Chapter 27 is a 2007 biographical drama film depicting the murder of John Lennon by Mark David Chapman. It was written and directed by Jarrett Schaefer, based on the 1992 book Let Me Take You Down by Jack Jones, produced by Robert Salerno, and stars Jared Leto as Chapman. The film takes place in December 1980, and is intended to be an exploration of Chapman's psyche. Its title is a reference to J. D. Salinger's 1951 novel The Catcher in the Rye, which has 26 chapters, and suggests a continuation of the book.

As an independent production, it was picked up for distribution by Peace Arch Entertainment and premiered at the 2007 Sundance Film Festival where it received polarized reactions from critics. It later went into limited theatrical release in the United States on March 28, 2008. Chapter 27 was cited as one of the most controversial films of 2007. It received the Debut Feature Prize for Schaefer at the Zurich Film Festival, where Leto also won Best Performance for his portrayal of Chapman.A similar film, The Killing of John Lennon, was released in the United States the previous year.