This chapter presents a historical outline of six key aspects of liberal political thought in Iran. Using a familiar schematic from mainstream histories of liberal thought, these are grouped into two broad categories of “liberal antipathies” (anti-traditionalism, anti-absolutism, and anti-imperialism) and “liberal prescriptions” (liberal nationalism, constitutionalism, and pluralism). These aspects, the chapter argues, combine to form the substantive core of much thinking and political action by Iranian liberals since the late nineteenth century. The common denominator linking these seemingly disparate elements into a coherent liberal project, the chapter shows, is an aversion to arbitrary exercises of power at the expense of individual liberty, the rule of law, and national sovereignty. Although by no means exhaustive, these aspects are introduced through the political thoughts and actions of Iranian reformers, intellectuals, politicians, journalists, and activists.