This is an open access title available under the terms of a CC BY-NC-ND 4.0 International license. It is free to read at Oxford Academic and offered as a free PDF download from OUP and selected open access locations. Leading multinational technology companies like Alphabet, Meta, Twitter, TikTok, and Microsoft now operate sprawling, complex systems to govern online behavior. These technical and bureaucratic infrastructures, commonly termed "content moderation" or "trust and safety," were developed in an effort to keep illegal and harmful material--such as child abuse imagery, hate speech, and incitement to extremist violence--out of sight and out of mind. But recently, they have been mired with scandal, and increasingly are in the public crosshairs. In The Politics of Platform Regulation, Robert Gorwa outlines how governments are shaping the emerging space of online safety. Through case studies from Germany, the United States, New Zealand, and Australia, and insights gleaned from ongoing policy debates in Brazil, India, and China, Gorwa explores the domestic and international politics that influence how, why, and when platform regulation comes into being. Going beyond existing work that explores the hidden private rules and practices increasingly shaping our online lives, The Politics of Platform Regulation is a measured empirical and theoretical account of how the state is pushing back.