As a psychological construct, the self has long occupied a preeminent place in both psychological and management theories regarding human behavior. In fact, the self is among the most widely studied concepts in the social sciences. The substantial attention afforded the self as a topic of research is hardly surprising given that it has been viewed as a primary locus of human motivation and agency, as well as judgment and decision making. This entry first describes some of the prominent definitions and conceptions of the self and summarizes some of the major constructs associated with it. The next section then elaborates on why the self—and theory about the self—is so important to organizational theory and management practice. The concluding section outlines some of the most recent and important developments in the conception of the self and its role in organizational life.