On June 12, 2016, Omar Mateen, a 29-year-old man, killed 49 people and wounded 53 more in a mass shooting at Pulse, a gay nightclub in Orlando, Florida, United States. Orlando Police officers shot and killed him after a three-hour standoff.

In a 9-1-1 call made shortly after the shooting began, Mateen swore allegiance to the leader of the Islamic State of Iraq and Syria, Abu Bakr al-Baghdadi, and said the U.S. killing of Abu Waheeb in Iraq the previous month "triggered" the shooting. He later told a negotiator he was "out here right now" because of the American-led interventions in Iraq and in Syria and that the negotiator should tell the United States to stop the bombing. The incident was deemed a terrorist attack by FBI investigators.

Pulse was hosting a "Latin Night", and most of the victims were Latino. It is the deadliest incident in the history of violence against LGBT people in the United States, as well as the deadliest terrorist attack in the U.S. since the September 11 attacks in 2001, and was the deadliest mass shooting by a single gunman in U.S. history until the 2017 Las Vegas shooting.