Under Siege 2: Dark Territory is a 1995 American action thriller film directed by Geoff Murphy, starring Steven Seagal as the ex-Navy SEAL, Casey Ryback. Set on board a train traveling through the Rocky Mountains from Denver to Los Angeles, it is the sequel to the 1992 film Under Siege also starring Seagal. The title refers to the railroading term that the subject train was travelling through dark territory, a section of railroad track that has no train signals and in which communications between train dispatchers and the railroad engineers were impossible.

The film was produced by Seagal along with Arnon Milchan and Steve Perry. The film's cast also included Eric Bogosian, Everett McGill, Morris Chestnut, Peter Greene, Kurtwood Smith and Katherine Heigl. In addition to Seagal, Nick Mancuso, Andy Romano, and Dale Dye also reprised their roles from the first film.