This article reviews research and interventions that have developed around a model of psychological well-being introduced over two decades ago to address neglected aspects of positive functioning, such as purposeful engagement in life, realization of personal talents, and enlightened self-knowledge. The conceptual origins of this model are revisited, and scientific products from six thematic areas are examined: (1) how well-being changes across adult development and later life; (2) personality correlates of well-being; (3) how well-being is linked with family experiences; (4) how well-being relates to work and other community activities; (5) connections between well-being and health, including biological risk factors; and (6) how psychological well-being can be promoted through clinical and intervention studies. These topics illustrate a flourishing interest across diverse scientific disciplines in understanding adults as striving, meaning-making, proactive organisms actively negotiating life's challenges. A key message is that increasing evidence supports the health-protective features of psychological well-being in reducing disease risk and promoting longevity. A recurring and increasingly important theme is resilience—the capacity to maintain or regain well-being in the face of adversity. Implications for future research and practice are considered. The model of psychological well-being, rooted in Aristotle's concept of eudaimonia, emphasizes meaning-making, self-realization, and striving. It has been operationalized through six dimensions: purpose in life, autonomy, personal growth, environmental mastery, positive relationships, and self-acceptance. These dimensions have been validated through extensive psychometric research, with the 14-item version widely used in scientific studies. The model has been linked to various aspects of health and well-being, including development and aging, personality correlates, family experiences, work and other life engagements, health and biological research, and clinical and intervention studies. Research shows that well-being is influenced by factors such as personality traits, social relationships, and coping strategies. It also plays a role in predicting health outcomes, including chronic conditions, mental health, and mortality. Studies have shown that higher levels of well-being are associated with better health, lower levels of stress, and greater resilience. Additionally, well-being has been linked to biological markers such as cortisol levels, immune function, and gene expression. Overall, the model of psychological well-being has been shown to have significant implications for health and well-being, with resilience being a key factor in maintaining or regaining well-being in the face of adversity.This article reviews research and interventions that have developed around a model of psychological well-being introduced over two decades ago to address neglected aspects of positive functioning, such as purposeful engagement in life, realization of personal talents, and enlightened self-knowledge. The conceptual origins of this model are revisited, and scientific products from six thematic areas are examined: (1) how well-being changes across adult development and later life; (2) personality correlates of well-being; (3) how well-being is linked with family experiences; (4) how well-being relates to work and other community activities; (5) connections between well-being and health, including biological risk factors; and (6) how psychological well-being can be promoted through clinical and intervention studies. These topics illustrate a flourishing interest across diverse scientific disciplines in understanding adults as striving, meaning-making, proactive organisms actively negotiating life's challenges. A key message is that increasing evidence supports the health-protective features of psychological well-being in reducing disease risk and promoting longevity. A recurring and increasingly important theme is resilience—the capacity to maintain or regain well-being in the face of adversity. Implications for future research and practice are considered. The model of psychological well-being, rooted in Aristotle's concept of eudaimonia, emphasizes meaning-making, self-realization, and striving. It has been operationalized through six dimensions: purpose in life, autonomy, personal growth, environmental mastery, positive relationships, and self-acceptance. These dimensions have been validated through extensive psychometric research, with the 14-item version widely used in scientific studies. The model has been linked to various aspects of health and well-being, including development and aging, personality correlates, family experiences, work and other life engagements, health and biological research, and clinical and intervention studies. Research shows that well-being is influenced by factors such as personality traits, social relationships, and coping strategies. It also plays a role in predicting health outcomes, including chronic conditions, mental health, and mortality. Studies have shown that higher levels of well-being are associated with better health, lower levels of stress, and greater resilience. Additionally, well-being has been linked to biological markers such as cortisol levels, immune function, and gene expression. Overall, the model of psychological well-being has been shown to have significant implications for health and well-being, with resilience being a key factor in maintaining or regaining well-being in the face of adversity.