Purpose of the Study: Everyone wants to age successfully; however, the definition and criteria of successful aging remain vague for laypersons, researchers, and policymakers in spite of decades of research on the topic. This paper highlights work of scholars who made significant theoretical contributions to the topic. Design and Methods: A thorough review and evaluation of the literature on successful aging was undertaken. Results: Our review includes early gerontological definitions of successful aging and related concepts. Historical perspectives reach back to philosophical and religious texts, and more recent approaches have focused on both process- and outcome-oriented models of successful aging. We elaborate on Baltes and Baltes’ the...