This study investigated differences in children's and adolescents' experiences of harming their siblings and friends. Participants (N = 101; 7‐, 11‐, and 16‐year‐olds) provided accounts of events when they hurt a younger sibling and a friend. Harm against friends was described as unusual, unforeseeable, and circumstantial. By contrast, harm against siblings was described as typical, ruthless, angry, and provoked, but also elicited more negative moral judgments and more feelings of remorse and regret. Whereas younger children were more self‐oriented with siblings and other‐oriented with friends, accounts of harm across relationships became somewhat more similar with age. Results provide insight into how these two relationships serve as distinct contexts for sociomoral development.