Witness is a 1985 American neo-noir crime thriller film directed by Peter Weir. The film stars Harrison Ford and Kelly McGillis, with Josef Sommer, Lukas Haas, Jan Rubeš, Danny Glover, Alexander Godunov, Patti LuPone and Viggo Mortensen (in his feature film debut). Its plot focuses on a police detective protecting an Amish woman and her son, who becomes a target after he witnesses a brutal murder in a Philadelphia railway station.

Filmed in 1984, Witness was released theatrically by Paramount Pictures in February 1985. The film went on to become a sleeper hit, grossing over $116 million worldwide. At the 58th Academy Awards, it earned eight nominations, including Best Picture and Best Actor for Ford, winning Best Original Screenplay and Best Film Editing. It was also nominated for seven BAFTA Awards, winning one for Maurice Jarre's score, and six Golden Globe Awards. William Kelley and Earl W. Wallace won the Writers Guild of America Award for Best Original Screenplay and the 1986 Edgar Award for Best Motion Picture Screenplay presented by the Mystery Writers of America.