Half Moon Street is a 1986 American erotic thriller film directed by Bob Swaim and starring Sigourney Weaver, Michael Caine, Keith Buckley, and P. J. Kavanagh. The film is about an American woman working at a foreign research and policy institute in London who moonlights for a British escort service, becoming involved in the political intrigues surrounding one of her clients.

The film was based on the 1984 novel Doctor Slaughter by Paul Theroux. Despite the source material, the film and book have distinct endings.

Half Moon Street was the first RKO Pictures solo feature film produced in almost a quarter-century. The previous one was Jet Pilot, which had been released in 1957.