This study examined the role of child sex in the link between child emotion regulation (ER) and peer victimization. Three facets of ER (i.e., regulation coping, inhibition, dysregulation) were considered within the context of three emotions (i.e., anger, sadness, worry) using two reporters: children (n = 114; 62 % girls; M age = 9.3 years; 57 % White) and a maternal caregiver. Mothers and children completed questionnaires on children’s ER strategies and peer victimization. Results of correlation and moderation analyses suggested that ER related to victimization with patterns varying by child sex and emotion type. Specifically, girls with anger regulation difficulties were at greater risk for victimization compared to boys with anger regulation difficulties. For boys, inhibition of sadness and worry and dysregulated worry significantly related to increased victimization. Applications to ER theory as well as applied prevention/intervention efforts are discussed.