In baseball, a double play (denoted on statistics sheets by DP) for a team or a fielder is the act of making two outs during the same continuous playing action. In baseball slang, making a double play is referred to as "turning two", or as Ernie Harwell has coined it, "two for the price of one".

Double plays are also known as "the pitcher's best friend" because they disrupt offense more than any other play, except for the rare triple play. Pitchers often select pitches that make a double play more likely (typically a pitch easily hit as a ground ball to a middle infielder) and teams on defense alter infield positions to make a ground ball more likely to be turned into a double play. Because a double play ends an inning in a one-out situation, it makes the scoring of a run impossible in that inning. In a no-out situation with runners at first base and third base, the double play may be so desirable that the defensive team allows a runner to score from third base so that two outs are made and further scoring by the batting team is more difficult.

Double plays initiated by a batter hitting a ground ball (but not a fly ball or line drive) are recorded in the official statistic GIDP, an indicator of one form of batting ineptitude. Should a run score on a play in which a batter hits into a double play (the first-and-third or bases loaded, none-out situation), official rules of scoring deny the batter credit for an RBI, although the batter always gets credit for an RBI on a one-out groundout or a fielder's choice play in which a baserunner scores.

Double Play! is a 1957 jazz album featuring pianists Russ Freeman and André Previn.

Together with drummer Shelly Manne, the album includes eight baseball-themed original compositions by Freeman and Previn along with the standard Take Me Out to the Ball Game.

It is notable for the unusual two-piano instrumentation, and indeed was advertised at the time as the first time that two pianists recorded "modern jazz" together.