Under Siege is a 1992 American action thriller film directed by Andrew Davis and written by J. F. Lawton. It stars Steven Seagal as an ex-Navy SEAL who must stop a group of mercenaries, led by Tommy Lee Jones, on the U.S. Navy battleship Missouri.

Released on October 9, 1992, Under Siege was successful in critical and financial terms, receiving two Oscar nominations for sound production and is often considered Seagal's best film to date.  The musical score was composed by Gary Chang. It was followed by a 1995 sequel, Under Siege 2: Dark Territory, which was less positively received.