Retirement as a research topic has become increasingly prominent in the psychology literature. This article provides a review of both theoretical development and empirical findings in this literature in the past two decades. We first discuss psychological conceptualizations of retirement and empirical operationalizations of retirement status. We then review three psychological models for understanding the retirement process and associated antecedents and outcomes, including the temporal process model of retirement, the multilevel model of retirement, and the resource-based dynamic model for retirement adjustment. We next survey the empirical findings regarding how various individual attributes, job and organizational factors, family factors, and socioeconomic context are related to the retirement process. We also discuss outcomes associated with retirement in terms of retirees' financial well-being, physical well-being, and psychological well-being.