Crackdown is a 2007 action-adventure game developed by Realtime Worlds and published by Microsoft Game Studios for the Xbox 360. Crackdown was conceived by Realtime Worlds' founder, David Jones, who also created Grand Theft Auto and Lemmings.

Set in the fictional Pacific City, the player controls a biologically enhanced Agent, tasked with defeating three crime lords and their organized crime syndicates. The Agent's abilities improve by defeating both crime lords and their top subordinates, as well as by completing optional activities, such as street races and scavenger hunts. The gameplay is nonlinear: instead of following a rigid mission sequence, players are free to select the approach to completing their missions and activities. The game features a two-player cooperative play mode via Xbox Live. It was released worldwide in February 2007.

Crackdown, initially planned for release on the original Xbox console, was envisioned as a vast world in which players could experiment and explore freely. Microsoft Game Studios bundled specifically marked copies of Crackdown with an access code to the multiplayer test version of the much-anticipated Halo 3 Beta. The game sold 1.5 million copies in its first six months of release. It received critical acclaim from reviewers and is widely considered to be the best entry in the series. It has garnered several awards for its innovative gameplay. A sequel, Crackdown 2, was released in July 2010 by Ruffian Games without Jones' input, and Crackdown 3 was released for the Xbox One and Microsoft Windows in February 2019, initially to be again directed by Jones before he left to join Epic Games.