Despite the alleged discursive affinity between populist rhetoric and conspiracy theories, we know too little about how populist conspiracies are communicated by politicians, and how these messages activate individual-level support for populist ideas. In this setting, this article reports on a qualitative content analysis of leading (radical) right-wing populist politicians’ self-communication (Trump and Wilders) and an experiment in which the central content features of populist conspiracies are manipulated. The main findings indicate that populist conspiracy theories activate populist attitudes more than mere exposure to populist ideas. Together, this article shows how conspiracies are framed in populist actors’ communication, and how these populist conspiracy frames can fuel support for populist ideology in society.