Extant research has identified various effects of leader humor on subordinates and work groups. In contrast, less research has explored the influence of leader humor on leaders themselves and leaders’ subsequent behaviors. To address these issues, we drew from ego depletion theory and investigated when and how leader humor impacted leader workplace deviance. We argued that leader humor along with high impression management motive would bring increased ego depletion to leaders themselves and ultimately result in more leader workplace deviance. We (...) tested our theoretical model using a three-wave time-lagged field survey data collected from 103 leaders and 595 subordinates, as well as an experiment involving 487 leader participants, which provided overall support for our hypotheses. Our findings revealed the possible dark side of leader humor influencing both leaders themselves and organizations. Theoretical contributions and new avenues for future research are addressed. (shrink)