Looney Tunes: Back in Action is a 2003 American live-action/animated comedy film directed by Joe Dante and written by Larry Doyle. The plot follows the Looney Tunes characters Daffy Duck and Bugs Bunny (both voiced by Joe Alaskey) as they help aspiring daredevil Damian "D.J." Drake, Jr. (Brendan Fraser) and Warner Bros. executive Kate Houghton (Jenna Elfman) find the "blue monkey" diamond in order to prevent the evil Mr. Chairman (Steve Martin) of the Acme Corporation from using it to turn mankind into monkeys that will manufacture his products; the group also attempts to rescue D.J.'s father (Timothy Dalton), an actor and spy who has been captured by Mr. Chairman. The animation was directed by Eric Goldberg. It was made following the success of Space Jam (1996), to which it was originally developed as a direct sequel, titled Spy Jam.

The film was theatrically released in the United States on November 14, 2003 by Warner Bros. Pictures. It received more positive reviews than Space Jam, but was a box-office flop, grossing $68.5 million worldwide against an $80 million budget.

This was the final film to be scored by composer Jerry Goldsmith, who died less than a year after the film's release. This was also the final film to be produced by Warner Bros. Feature Animation. Along with this, it was also the last theatrically released feature film to prominently feature the Looney Tunes characters until 2021’s Space Jam: A New Legacy.