In this study, we test whether leader psychological flexibility moderates the relationship between leaders’ perceptions of work overload and leader–member exchange (LMX). A field study was conducted among 186 followers and 93 leaders from a Norwegian public service organization. Multisource field data demonstrate general support for the hypothesized relationships. The results of multilevel analyses showed that for leaders lower in psychological flexibility there was a negative relation between leaders’ perceptions of work overload and subordinates perceptions of LMX. Thus, psychological flexibility seemed to mitigate the negative implications of leaders’ work overload. Implications for future research and practice are discussed.