"Do-Over" is the first episode of the third season of the American television comedy series 30 Rock, and the thirty-seventh episode overall. It was written by the series' creator, executive producer and lead actress, Tina Fey and directed by series producer Don Scardino. The episode originally aired on NBC in the United States on October 30, 2008. Guest stars in this episode include Will Arnett, Marceline Hugot, and Megan Mullally.

The third season of 30 Rock, an American television comedy series, consists of 22 episodes and began airing on October 30, 2008, on the NBC network in the United States. The season was produced by Broadway Video, Little Stranger, and NBC Universal; the executive producers were series creator Tina Fey, Lorne Michaels, Marci Klein, David Miner, and Robert Carlock.