A key goal of feminists in psychology has been to understand and challenge social relations of inequality, privilege, and oppression. Several orienting assumptions of mainstream psychology present obstacles to achieving this goal. For example, one assumption is internalism—focusing on inner motives, traits, and capacities as the determinants of human behaviour, while ignoring the sociocultural context. Another is universalism—the assumption that psychological theories and explanations can hold for all people everywhere and at all times. The chapter also reviews the history of feminism in psychology and provides an overview of methods and practices utilized by feminist psychologists.