ABSTRACT The Islamic State, IS, is known for extreme violence and publishing and distributing extreme violent material online. IS’s public executions have previously been researched in the context of state legitimacy building, but this research has mostly focused on Western and/or foreign victims, leaving out other demographic groups, like local sexual and gender minorities, and what role their murders play in building IS’s legitimacy. This research analyses IS’s violence against sexual and gender minorities and how this violence helped build IS’s legitimacy regionally and internationally. To analyse a quasi-state actor with legitimacy aspirations, I develop a theoretical framework using Michel Foucault’s paradigms of sovereign, disciplinary and biopolitical power. Utilising visual and audio-visual material from 18 different executions of victims accused of homosexuality, I argue that the persecution and murders of sexual and gender minorities build IS’s legitimacy on two levels: the local and the international. Furthermore, the “Us vs. Them” dichotomy typical for terrorist organisations is also formed in these executions and becomes present on these two levels. The research demonstrates that the participation of audience, whether present or witnessing the executions online later, is at the heart of the rationality of power in these executions.