Gangster Squad is a 2013 American action thriller film directed by Ruben Fleischer and written by Will Beall, based on a non-fiction book by Paul Lieberman. The film stars Josh Brolin, Ryan Gosling, Nick Nolte, Emma Stone, Anthony Mackie, Giovanni Ribisi, Robert Patrick, Michael Peña and Sean Penn. Set in 1949, a group of real-life LAPD officers and detectives called the Gangster Squad are assigned to bring down crime kingpin Mickey Cohen.

After the script spent several years on the Black List, production began in September 2011 around Los Angeles, lasting through December. The film was originally set to be theatrically released September 7, 2012, but in the wake of the 2012 Aurora, Colorado, shooting, Warner Bros. pushed it back to a January 11, 2013, release to accommodate re-shoots, which took place in August 2012.

Gangster Squad received mixed reviews from critics and grossed $105 million worldwide.