The Kremlin Letter is a 1970 American spy thriller film in Panavision directed by John Huston and starring Richard Boone, Orson Welles, Max von Sydow, Bibi Andersson, Patrick O'Neal, and George Sanders. It was released in February 1970 by 20th Century-Fox.

The screenplay by Huston and Gladys Hill was based on the 1966 novel of the same name by Noel Behn, who had worked for the United States Army's Counterintelligence Corps. Said by reviewers to be "beautifully" and "engagingly" photographed, the film is a highly complex and amoral tale of bitter intrigue and espionage set in the winter of 1969–1970 at the height of the US–Soviet Cold War.

The Kremlin Letter was a commercial failure and thinly reviewed in 1970, but the film has gathered steady praise from some critics throughout the decades since its release. French filmmaker Jean-Pierre Melville called The Kremlin Letter "masterly" and "...saw it as establishing the standard for cinema."