Traumatic event exposure affects two in every three adolescents in the United States and there is the potential for numerous deleterious effects including higher levels of youth depression, anxiety, posttraumatic stress symptoms, and emotional and behavioral problems. Witnessing violence is one of the more common experiences associated with trauma exposure. Despite the ample research on mental health outcomes associated with witnessing violence, less is known about the extent to which parent–child relationships play a role in youth mental health outcomes when youth are exposed to violence. With a clinically relevant, diverse sample of 806 youth ages 12 years old who experienced maltreatment or were at risk of being maltreated, we tested hypotheses that the parent–child relationship quality would moderate the associations between witnessing violence and youth mental health outcomes. Results supported hypotheses for youths’ symptoms of anxiety, depression, dissociation, and posttraumatic stress. The study contributes to the trauma literature by determining that the quality of the parent–child relationship moderated the effects of witnessing violence on trauma outcomes.