The 2015 SummerSlam was the 28th annual SummerSlam professional wrestling pay-per-view (PPV) and livestreaming event produced by WWE. It took place on August 23, 2015, at the Barclays Center in Brooklyn, New York and would be the first of four consecutive SummerSlam events to take place at the arena. It was the first SummerSlam since 2008 to be held outside of Los Angeles as its Staples Center was the exclusive home for SummerSlam from 2009 to 2014. It was also the eighth SummerSlam to be held in the New York metropolitan area. The Izod Center in East Rutherford, New Jersey was originally supposed to host SummerSlam, but due to its closure in April 2015, the event was relocated. It was also the first SummerSlam to be four hours in length, a length previously reserved only for WrestleMania. This was also the last SummerSlam held before the reintroduction of the brand extension in July 2016. It was also the first major WWE event following the death of Roddy Piper.

SummerSlam is a professional wrestling event, produced annually since 1988 by the world's largest professional wrestling promotion, WWE. Dubbed "The Biggest Party of the Summer", it is considered WWE's second biggest event of the year behind their flagship event, WrestleMania. It is also considered one of the company's five biggest events of the year, along with WrestleMania, Royal Rumble, Survivor Series, and Money in the Bank, referred to as the "Big Five". The event has been broadcast on pay-per-view (PPV) since the inaugural 1988 event and via livestreaming since the 2014 event.