In this study, we examined students' perceptions of peer aggression occurring within their school environment and how these perceptions are interconnected with both social media rumination and distress. Social media usage is associated with a range of negative mental health and interpersonal outcomes for adolescents. Social media use can increase youth's vulnerability to peer victimization and psychosocial difficulties. In addition, ruminating when sad or stressed has been linked to elevated distress for youth experiencing peer aggression. Yet rumination specifically regarding social media activities has not been investigated in relation to peer aggression and distress, nor has the degree to which students perceive peer aggression occurring at school been included in these investigations. Participants were 169 high school students (age, M = 15.89, SD = .87), largely identifying as Black/African American and female, who completed surveys as part of a larger program working with at-risk youth in a Midwestern, urban city. We found that social media rumination mediated the relationship between perceptions of bullying at school and feelings of distress, but mediation was not supported when examining student perceptions of cyberbullying frequency and youth distress. In the case of bullying, rumination may disrupt other forms of coping-such as positive cognitive distractions-that would ameliorate symptoms of distress. Furthermore, we present evidence that social media rumination is experienced by, and has different influences on, youth. We highlight the need for differentiated intervention and prevention efforts regarding these two forms of peer aggression. Future research may be justified to examine these possibilities.