SummerSlam (2009) was a professional wrestling pay-per-view (PPV) event produced by World Wrestling Entertainment (WWE), which took place on August 23, 2009, at Staples Center in Los Angeles, California and was the first of six consecutive annual SummerSlam events to take place at the arena. It was presented by 7-Eleven. It was the twenty-second annual SummerSlam event and featured talent from the Raw, SmackDown, and ECW brands. Eight matches were contested on the event's card.

The show was what is known as a supercard, which featured more than one main event match. 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. Other matches featured on the show were WWE Intercontinental Champion Rey Mysterio versus Dolph Ziggler, Montel Vontavious Porter (MVP) against Jack Swagger, Chris Jericho, and The Big Show defending the Unified WWE Tag Team Championship against Cryme Tyme (Shad Gaspard and JTG), and Kane facing The Great Khali. The event received 369,000 buys, down from the SummerSlam 2008 figure of 477,000 buys.