This research examined how leader illegitimacy affects leaders' and subordinates' responses to relinquishing power decisions. The processes underlying responses to leader illegitimacy and relinquishing power were also examined. Across four studies, participants were placed in leader roles (Studies 1a/1b) or subordinate roles (Studies 2a/2b) in an online competition. In Studies 1a/1b, participants assigned a leadership role learned, via a leadership skills test, that their leadership was illegitimate or legitimate. By contrast, in Studies 2a/2b, participants assigned a subordinate role were confronted with either an illegitimate leader who retained their power after performing poorly or a legitimate leader who received the leader role after a poor‐performing leader had relinquished their power. Results demonstrated that leaders who felt they did not belong in their leadership role relinquished more power when their leadership was illegitimate (vs. legitimate) and subordinates who felt less in control and greater anger supported illegitimate (vs. legitimate) leaders less.