Values play an outsized role in the visions, critiques, and discussions of politics, religion, education, and family life. Despite all the attention values receive in everyday discourse, their systematic study took hold in mainstream psychology only in the 1990s. This review discusses the nature of values and presents the main contemporary value theories, focusing on the theory of basic personal values. We review evidence for the content and the structure of conflict and compatibility among values found across cultures. We discuss the assumptions underlying the many instruments developed to measure values. We then consider the origins of value priorities and their stability or change over time. The remainder of the review presents the evidence for the ways personal values relate to personality traits, subjective well-being, and the implications of value differences for religiosity, prejudice, pro- and antisocial behavior, political and environmental behavior, and creativity, concluding with a discussion of mechanisms that link values to behavior. Expected final online publication date for the Annual Review of Psychology, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.