Background: Our objective is to describe violence-related injuries to early adolescents that occurred at school, resulting in emergency department (ED) evaluation. Methods: This retrospective cohort study at an urban academic pediatric ED in Baltimore, MD, identified patients 10-15 years old who presented with an injury from intentional, interpersonal violence that occurred at school between January 2019-December 2020. Descriptive statistics were used to summarize patient and event characteristics. Results: Of 819 youth 10-15 years of age evaluated for a violence-related injury, school was the location in 115 cases (14.0%). All events occurred prior to the statewide stay at home order (March 30, 2020). School-injured youth had a mean age of 12.7 ± 1.7 years and were predominantly male (64.3%). Of the 115 cases, 75 (65.2%) involved an altercation with a peer, 26 (22.6%) involved a teacher or school staff, 6 (5.2%) involved a family member, 1 (0.9%) involved police, 6 (5.2%) involved an unknown party, and 1 (0.9%) involved an unrelated but known adult. All injured youth were discharged from the ED. Conclusions: School-based violence is a well-recognized cause of traumatic injuries to adolescents and may involve peers, teachers, or school staff.