The 2009 SummerSlam was a professional wrestling pay-per-view (PPV) event produced by World Wrestling Entertainment (WWE). It was the 22nd annual SummerSlam and took place on August 23, 2009, at Staples Center in Los Angeles, California, marking the first of six consecutive SummerSlam events to take place at the arena. The event featured wrestlers from the promotion's Raw, SmackDown, and ECW brand divisions, in turn marking the last SummerSlam to include the ECW brand.

Eight matches were contested on the event's card. The main events of the evening included CM Punk defeating Jeff Hardy in a Tables, Ladders, and Chairs match to win the World Heavyweight Championship for a third time, Randy Orton retaining the WWE Championship against John Cena after the match was restarted multiple times, Christian retaining the ECW Championship against William Regal, and D-Generation X's Triple H and Shawn Michaels defeating The Legacy's Cody Rhodes and Ted DiBiase. Also on the show, WWE Intercontinental Champion Rey Mysterio Jr. defeated Dolph Ziggler and Chris Jericho and The Big Show defended the Unified WWE Tag Team Championship against Cryme Tyme. The event received 369,000 buys, down from the SummerSlam 2008 figure of 477,000 buys.