The purpose of this chapter is to provide an overview, analysis, and synthesis of theory and research on the mediatization of politics. The mediatization of politics is defined as a long-term process through which the importance of the media and their spill-over effects on political processes, institutions, organizations, and actors has increased. Four dimensions can be distinguished in this process, related to the importance of media as source of information about politics and society, the autonomy of media institutions from other social and political institutions, and the extent to which media content and political institutions, organizations, and actors respectively are guided by media logic or political logic. Both media logic and political logic are conceptualized as three-dimensional concepts. While media logic is conceptualized as shaped by professionalism, commercialism, and media technology, political logic is conceptualized as shaped by polity, policy, and politics. The chapter also analyzes the concepts of media influence and media effects within the context of the mediatization of politics. The chapter concludes by identifying five challenges for further theory and research on the mediatization of politics.