(500) Days of Summer is a 2009 American romantic comedy film directed by Marc Webb, written by Scott Neustadter and Michael H. Weber, and produced by Mark Waters. The film stars Joseph Gordon-Levitt and Zooey Deschanel as Tom and Summer respectively, and in a nonlinear narrative structure, Tom chronicles the story of his relationship with Summer.

As an independent production, the film was picked up for distribution by Fox Searchlight Pictures and premiered at the 25th Sundance Film Festival. It received positive critical reviews and became a successful "sleeper hit", earning $60.7 million in worldwide returns, far exceeding its $7.5 million budget. Many critics lauded the film as one of the best from 2009 and drew comparisons to other acclaimed films such as Annie Hall (1977) and High Fidelity (2000). The movie is considered as a cult classic.

The film received Best Original Screenplay and Best Screenplay awards at the 14th Satellite Awards and 25th Independent Spirit Awards, respectively, as well as two nominations at the 67th Golden Globe Awards: Best Motion Picture – Musical or Comedy and Best Actor – Musical or Comedy (Gordon-Levitt).