--- - |2+ Abstract Objective Although there is a robust connection between dispositional personality traits and well‐being, relatively little research has comprehensively examined the ways in which all Big Five personality states are associated with short‐term experiences of well‐being within individuals. We address three central questions about the nature of the relationship between personality and well‐being states: First, to what extent do personality and well‐being states covary within individuals? Second, to what extent do personality and well‐being states influence one another within individuals? Finally, are these within‐person relationships moderated by dispositional personality traits and well‐being? Method Two experience sampling studies (N = 161 and N = 146) were conducted over 2 weeks. Results Across both studies, all Big Five personality states were correlated with short‐term experiences of well‐being within individuals. Individuals were more extraverted, emotionally stable, conscientious, agreeable, and open in moments when they experienced higher well‐being (greater self‐esteem, life satisfaction and positive affect, and less negative affect). Moreover, personality and well‐being states dynamically influenced one another over time within individuals, and these associations were not generally moderated by dispositional traits or well‐being. Conclusions Behavior and well‐being are interconnected within the context of the Big Five model of personality. - Journal of Personality, EarlyView.