--- - |2 The present study uses a within‐person approach to provide insights into day‐specific dynamics in the relation between self‐control demands at work and well‐being. Integrating arguments derived from the Limited Strength Model of Self‐Control and research on spillover processes, we develop and test a theoretical model of how the adverse effects of day‐specific self‐control demands at work may spill over to the home domain. Specifically, we propose ego depletion at home (an indicator of regulatory resource depletion) as a mediator linking self‐control demands on a given working day to reduced subjective vitality at home (an indicator of well‐being). Furthermore, we suggest that daily psychological detachment moderates this indirect relationship to the effect that high detachment prevents the spillover of the adverse effects of self‐control demands to the home domain. Results from our daily diary study across ten days (N = 86 employees) provide support for the proposed moderated mediation model, demonstrating that daily psychological detachment buffers the effect of self‐control demands on ego depletion, thereby disrupting the indirect effect of self‐control demands on subjective vitality at home. The study underlines the importance of within‐person approaches for examining the adverse effects of self‐control demands, and provides further evidence for the immediate resource‐replenishing benefits of daily detachment levels. - Applied Psychology, EarlyView.