Social cognitive theory focuses on the reciprocal interaction of the person, environment, and behavior and provides a description of the ways in which individuals initiate and maintain behaviors, taking into consideration their social environment. The main operative constructs in the theory are outcome expectancies and self-efficacy. Outcome expectancies pertain to the anticipated consequences of one’s actions. Self-efficacy reflects a subjective estimate of the amount of personal control an individual expects to have in any given situation. The theory has been applied as a basis for changing behavior in a wide variety of disciplines and settings, including sport, education, career and occupational development, and mental and physical health settings. Interventions have targeted change in self-efficacy, outcome expectancies, or both, assuming that an improvement in these beliefs translates to changes in behavioral outcomes. A considerable body of evidence supporting theory predictions has accumulated. Research has underscored the beneficial effects of such interventions on target behaviors and outcomes such as academic achievement, career promotion, job search, smoking cessation, participation in physical exercise, and eating a healthy diet across a broad array of populations and settings. The theory has been influential in the development of other theories that have adopted parts of it, in particular, the self-efficacy construct.