Training Day is a 2001 American crime thriller film directed by Antoine Fuqua and written by David Ayer. It stars Denzel Washington as Alonzo Harris and Ethan Hawke as Jake Hoyt, two LAPD narcotics officers over a 24-hour period in the gang-ridden neighborhoods of Westlake, Echo Park, and South Central Los Angeles. It also features Scott Glenn, Eva Mendes, Cliff Curtis, Dr. Dre, Snoop Dogg, and Macy Gray in supporting roles.

Training Day was released on October 5, 2001, by Warner Bros. Pictures. It received generally positive reviews from critics, who praised Washington and Hawke's performances but were divided on the screenplay. It was a commercial success, grossing $104 million worldwide against a production budget of $45 million.

The film received numerous accolades and nominations, with Washington's performance earning him the Academy Award for Best Actor and Hawke being nominated for Best Supporting Actor at the 74th Academy Awards.A television series based on the film, produced by Jerry Bruckheimer, was announced in August 2015 and premiered on February 2, 2017, on CBS, but was cancelled after one season.

On February 28, 2022, a prequel titled Training Day: Day of the Riot was reported to be in development; in an interview, Fuqua said, “we’re trying to find a director to do it at the moment, you know, and get the script right. That sort of thing. So it’s in development.”