The fifteenth season of the American animated television series The Simpsons aired from Sunday, November 2, 2003, to Sunday, May 23, 2004. The season contains five hold-over episodes from the season 14 (EABF) production line. The most watched episode had 16.2 million viewers and the least watched had 6.2 million viewers. Season 15 was released on DVD and Blu-ray in Region 1 on December 4, 2012, Region 2 on December 3, 2012, and Region 4 on December 12, 2012.

The fourteenth season of the American animated television series The Simpsons was originally broadcast on the Fox network in the United States between November 3, 2002, and May 18, 2003, and was produced by Gracie Films and 20th Century Fox Television. The show runner for the fourteenth production season was Al Jean, who executive produced 21 of 22 episodes. The other episode, "How I Spent My Strummer Vacation", was run by Mike Scully. The season was the first to use digital ink-and-paint for most of its episodes, though four episodes were hold-overs from season 13's production run and used traditional ink-and-paint. A fifth season 13 holdover episode, which was the first episode of season 14, used digital ink-and paint like the rest of the season. The fourteenth season has met with mostly positive reviews and won two Primetime Emmy Awards, including Outstanding Animated Program, four Annie Awards and a Writers Guild of America Award. This season contains the show's 300th episode, "Barting Over".