Before Sunset is a 2004 American romantic drama film directed by Richard Linklater, who co-wrote the screenplay with Ethan Hawke and Julie Delpy, from a story by Linklater and Kim Krizan. It is the first film by Warner Independent Pictures. The sequel to Before Sunrise (1995) and the second installment in the Before trilogy, Before Sunset follows Jesse (Hawke) and Céline (Delpy) as they reunite nine years later in Paris.

Linklater, Krizan, Hawke, and Delpy began developing a larger budget sequel in the 1990s, but failed to secure funding to begin production. After writing the film independently, with portions inspired by Hawke's divorce from Uma Thurman, the writers came together in 2003 and incorporated elements of their individual screenplays, as well as other scenes written during development of Before Sunrise, to create the final screenplay. Principal photography took place entirely in Paris, and the film is considered to take place in real time. Delpy also contributed original music to the film's soundtrack.

Before Sunset premiered at the Berlin International Film Festival on February 10, 2004, and was theatrically released in the United States on July 2, 2004. It grossed $15 million worldwide and received widespread critical acclaim, particularly for Linklater's direction, the performances and chemistry of its leads, and its screenplay. It received numerous accolades, being nominated for the Academy Award for Best Adapted Screenplay, and appeared on many publications' lists of the best films of the year, with some calling it one of the best of the decade. It was followed by a third film, Before Midnight, in 2013.