Mohammed Emwazi was a British militant of Kuwaiti origin seen in several videos produced by the Islamist extremist group Islamic State (IS) showing the beheadings of a number of captives in 2014 and 2015. A group of his hostages nicknamed him "John" since he was part of a four-person terrorist cell with English accents whom they called 'The Beatles'; the press later began calling him "Jihadi John".

Beginning in 2014, a number of people from various countries were beheaded by the Islamic State (IS), a radical Sunni Jihadist group operating in Iraq and Syria as well as elsewhere. In January 2014, a copy of an IS penal code surfaced describing the penalties it enforces in areas under its control, including multiple beheadings. Beheading videos have been frequently posted by IS members to social media. Several of the recorded beheadings were conducted by Mohammed Emwazi, whom the media referred to as "Jihadi John" before his identification. The beheadings received wide coverage around the world and attracted international condemnation. Political scientist Max Abrahms posited that IS may be using well-publicized beheadings as a means of differentiating itself from Al-Qaeda in Iraq, and identifying itself with Khalid Sheikh Mohammed, the al-Qaeda member who beheaded Daniel Pearl. The publicised beheadings represent a small proportion of a larger number of total people killed following capture by IS.