Research on the consequences of acting out of character yielded mixed findings. One reason might be that these studies have typically focused on one personality dimension a time, while personality is multidimensional. In the present paper, we study the affective consequences of acting out of character, accounting for personality’s multidimensional nature. Additionally, we study the mechanisms underlying this association by examining the mediating role of depletion. In three repeated measures datasets, we show that within-person fluctuations in the extent to which one acts out of character are associated with lower levels of positive affect and higher levels of negative affect. Moreover, in one of the three studies we demonstrate that this association might be explained by the higher levels of depletion associated with acting out of character. These findings are one of the first to show that deviating from one’s personality profile can be depleting, and that this is associated with affective costs.