Public service motivation (PSM) refers to an individual’s motivation to contribute to society. It relates to ideas about society, and about what public servants are and how they should behave, that have persisted for more than 2,500 years. Despite this heritage, PSM was only formally conceptualized in the 1990s. The concept of PSM has traditionally been linked to several beneficial outcomes, such as public performance and public servants’ satisfaction, but recently also to negative outcomes, such as burnout and rule-breaking. While PSM is an individual-level concept, the role of the social environment is crucial to understanding PSM. On the one hand, social institutions play an important role in creating individual-level PSM through socializing mechanisms. Institutions such as the family and workplace, and other structured value-based interaction patterns, correlate with the prevalence of individual PSM. On the other hand, to render outcomes, interaction with the environment—in terms of fit—is necessary, because PSM cannot exert influence outside a context where public values are prominent. As most research focuses on public servants in their work environment, this fit mostly entails a match of the individual public servant with the organization or the job. If this fit is lacking, little or no PSM occurs. Although PSM research was initially a theoretical and psychometric exercise, it is increasingly put to practical use.