No defense of the liberal-democratic state can do without political obligation, yet existing theories cannot provide a successful account of obligation. Existing accounts of obligation cannot parry critiques from rival theories, nor refute philosophical anarchists' attack on obligation. To move discussion of obligation forward, this dissertation offers an alternative solution to the `voluntarist paradox' of liberal-democratic political obligation. While liberal ideas about the individual require that any obligation to obey be assumed through a voluntary act, individuals do not voluntarily assume obligations frequently enough to support legitimacy claims. In response to this paradox, most scholars deploy non-voluntary justifications for a general obligation to obey, while philosophical anarchists deny that such an obligation exists at all. In contrast, I argue that overcoming the voluntarist paradox requires a radically different view of political obligation. Thus, while most obligation theories begin with a general requirement to obey and look for its source, my account begins with voluntary action, and asks what requirements it can yield. I show that the conventional goal of political obligation generates the impasse between obligation's proponents and philosophical anarchists, hinders analysis of democratic self-government, and inaccurately depicts obedience and law. Instead, I define political obligation as a voluntarily-assumed `binding requirement to take political action,' a broader category that also includes non-voluntary duties. Voluntarist obligation, I show, is incompatible with a general requirement to obey. Rather, political obligation concerns the whole variety of political actions one can voluntarily commit to perform: it is a voluntarist practice that expresses one's freedom to create, shape, and revise sociopolitical institutions and practices. This approach to political obligation lets us address often-neglected features of liberal-democratic politics because it goes beyond state-imposed requirements, and looks to the individual actions that generate those requirements. In liberal democracies, the voluntary acts of state agents develop, interpret, and enforce laws and policy, and individuals affect the state by voluntarily exercising their rights and taking political action. Because my account of political obligation connects voluntarily-assumed requirements to the conditions of political self-determination, it provides a stronger foundation for liberal democracy, and facilitates analysis of normative demands on political actors.