This chapter examines the political economy of water markets. It traces key debates about water markets, and examines how and why these debates have evolved since the 1970s. Experiments with water markets over the past 40 years have generated lessons about the politics, institutional design and performance of reforms to water rights and river basin governance institutions. Drawing on contrasting experiences with water markets in Australia, the US and China, the analysis demonstrates that strong government and community roles are necessary for water markets to respond effectively and equitably to water scarcity.