Populism is one of the most pressing and thriving political issues in current democracies, as populist actors are extremely successful around the globe and increasing in importance. This has raised scholarly concerns to discuss this development also from a communication science perspective and explain the relation of political actors and their utilization of populist communication elements. This thesis answers two major research aims by first providing a conceptualization and operationalization of populist communication that combines and integrates both ideology-centered and discourse-centered definitions of populism and arguing that populist communication is a combination of ideology and style. By comparing the utilization of populist communication across different media channels, a variety of political actors and different political issues, this thesis secondly investigates and explains who expresses the populist messages and styles and to what extent populist communication is spread. With five comparative studies and the overarching synopsis, this thesis demonstrates that populist communication is especially dependent on certain opportunity structures and flourishes when populism affine factors, such as social media communication, party extremism or a high affinity to populism related issues, are combined.