The 2015 Night of Champions was the ninth annual Night of Champions professional wrestling pay-per-view (PPV) and livestreaming event produced by WWE. It took place on September 20, 2015, at the Toyota Center in Houston, Texas. This was the second Night of Champions held at this venue, after Vengeance: Night of Champions in 2007. As per the theme of the event, every championship promoted on WWE's main roster at the time was defended. The event was replaced by the similarly themed Clash of Champions in 2016; however, WWE revived Night of Champions in 2023. This in turn made the 2015 event the final Night of Champions to be held before the reintroduction of the brand extension in July 2016.

Eight matches were contested at the event, with one match on the Kickoff pre-show. In the main event, Seth Rollins defeated Sting to retain the WWE World Heavyweight Championship. In the penultimate match, John Cena defeated Rollins to win the WWE United States Championship. In other prominent matches, Kevin Owens defeated Ryback to win the WWE Intercontinental Championship, and Charlotte defeated Nikki Bella to win the WWE Divas Championship. With her win, Charlotte became the final holder of the title before it was retired at WrestleMania 32 in April 2016. The event, which included Sting's sole PPV main event and title match in WWE, which would in turn be his final match in the promotion, generated 77,000 buys (up from the previous year's 48,000).