This article examines the concept of accountability from various disciplinary lenses in order to develop an integrated understanding of the term. Special attention is devoted to principal—agent perspectives from political science and economics. An integrated framework is developed, based on four central observations. (1) Accountability is relational in nature and is constructed through inter- and intraorganizational relationships. (2) Accountability is complicated by the dual role of nonprofits as both principals and agents in their relationships with other actors. (3) Characteristics of accountability necessarily vary with the type of nonprofit organization being examined. (4) Accountability operates through external as well as internal processes, such that an emphasis on external oversight and control misses other dimensions of accountability essential to nonprofit organizations. The analysis draws from the experiences of both Northern and Southern nonprofits, that is, organizations based in wealthy industrialized regions of the world (the global North) and those in economically poorer areas (the South).