Season five of Supernatural, an American television series, has begun airing on September 10, 2009. This is the fourth season to air on theCW television network. Season five regular cast members include Jared Padalecki, Jensen Ackles and Misha Collins. Mark Pellegrino plays the role of Lucifer, who was freed from Hell at the end of Season 4. Paris Hilton guest starred for the episode "Fallen Idols", in which she played a pagan god that takes the form of various well-known faces including Paris Hilton. Both Jo and her mother Ellen Harvelle returned, as Kripke revealed at the 2009 Comic-Con. Additionally, hunter Rufus and the prophet Chuck make appearances. Season 5 focuses on the mending of Sam and Dean's wrecked relationship and the Apocalypse.

In this table, the number in the first column refers to the episode's number within the entire series, whereas the number in the second column indicates the episode's number within that particular season. "U.S. viewers in millions" refers to how many Americans who watched the episode live or on the day of broadcast.