The Descent is a 2005 British horror film written and directed by Neil Marshall. The film stars actresses Shauna Macdonald, Natalie Mendoza, Alex Reid, Saskia Mulder, Nora-Jane Noone and MyAnna Buring. The plot follows six women who enter an uncharted cave system and struggle to survive against the monstrous critters inside.

Filming took place in the United Kingdom. Exterior scenes were filmed at Ashridge Park, Hertfordshire, and in Scotland. Because the filmmakers considered it too dangerous and time-consuming to shoot in an actual cave, interior scenes were filmed on sets built at Pinewood Studios near London designed by Simon Bowles.

The Descent opened in cinemas in the United Kingdom on 8 July 2005. It premiered in the 2006 Sundance Film Festival and released on 4 August 2006 in the United States. The film received positive reviews with praise for the performances, cinematography and Marshall's direction. It was also a box-office success, grossing $57.1 million worldwide against a £3.5 million budget. Since its release, it has been regarded as one of the best horror films of the 2000s.

A sequel, titled The Descent Part 2, was released in 2009.