Burnout is an important marker of employee well-being that is often characterized by three primary symptoms: exhaustion, depersonalization, and reduced efficacy. In this chapter, we present an historical overview of the burnout literature with an emphasis on fit, social exchange relationships, and the consequences of burnout. We follow that with a discussion of more recent developments in the study of burnout and outline emerging opportunities in the study of burnout, including relationships between burnout and emotions, physiological issues and measures, and interventions.