<p>Different philosophical strands have developed distinct well-being conceptions, which are nevertheless strongly linked. For instance, many typical well-being components in eudaimonic philosophies correlate with subjective life assessment measures. Existing empirical research also provides many insights into which factors determine human well-being, such as health and the quality of relationships. However, the causal ordering of these factors is often not explicitly considered, although doing so would be crucial for the identification of intervention points and a correct estimation of effect sizes in empirical studies. In response to these two observations, we propose a unified causal framework of the main pathways determining human well-being in its different conceptions, with a focus on those prominent in sustainability research and the subjective well-being community. The framework considers environmental, economic, societal, political, social, and psychological factors and shows how they interact. It combines insights from theories of human needs, the capabilities approach, and research on subjective indicators. We illustrate the use of the framework with examples of societal interventions on well-being, environmental impacts, and sustainable well-being policies.</p>