Existing research provides substantial evidence of the positive effects of leader humour on followers and their teams. However, less attention has been given to understanding how such behaviour benefits leaders. This study, grounded in the Conservation of Resources theory, introduces and tests a model that clarifies the mechanisms and conditions under which leader humour benefits these individuals. The study findings, derived from data collected from 137 supervisors in an experience sampling study and 134 supervisors in a three-wave field study, consistently show a positive correlation between leader humour and leader psychological capital, which subsequently enhances leader work engagement. Moreover, the magnitude of this positive effect depends on the leader’s political skill level, with those possessing high political skill reaping greater benefits from leader humour. The results suggest that leader humour is an effective method for supervisors to gain psychological resources.