Anger is commonly associated with aggression. Inefficient anger-coping strategies increase negative affect and deplete the regulatory resources needed to control aggressive impulses. Factors linked with better emotion regulation may then weaken the relationship between anger and aggression. The current work explored one factor associated with emotion regulation-differentiating one's emotions into discrete categories-that may buffer angry people from aggression. Three diary studies (N = 628) tested the hypothesis that emotion differentiation would weaken the relationship between anger and aggression. In Study 1, participants high in emotion differentiation reported less daily aggressive tendencies when angry, compared to low differentiators. In Study 2, compared to low differentiators, high differentiators reported less frequent provocation in daily life and less daily aggression in response to being provoked and feeling intense anger. Study 3 showed that high daily emotional control mediated the interactive effect of emotion differentiation and anger on aggression. These results highlight the importance of considering how angry people differentiate their emotions in predicting their aggressive responses to anger.