Well-being has received increasing attention from researchers and policymakers, and its promotion could be considered pivotal to handle the challenges of aging populations. However, many different well-being concepts have been used inconsistently, and it remains unclear what the concept of well-being refers to among the oldest segments of the population. Hence, there is a need for a more cohesive understanding of the meaning of the concept in this particular context. The aim of this study was to review the scientific literature to examine the conceptualization of well-being in very old age. Rodgers’ evolutionary concept analysis was applied as a guiding framework. A search through scientific databases generated a sample of 568 unique articles published between 2009 and 2019, of which 49 were included in the final analysis. Four main attributes of well-being in very old age were identified: multifaceted; intertwined with health and quality of life; ability to adapt; and part of successful aging. Furthermore, the antecedents and consequences of well-being in very old age, as well as related concepts, were summarized and discussed. The results revealed that there was a transition between general aspects of well-being and specific aspects of very old age. Particularly adaptation appears to be a crucial part of well-being in very old age, and methods of supporting the ability to adapt should therefore be tested and implemented.