Integrating social and emotional learning (SEL) programming throughout curricula to support the development of healthy behaviors and prevent violence is critical for a comprehensive approach to school health. This study used a post-test comparison design to evaluate a healthy relationships program for eighth grade students that applies a SEL approach. The program was adapted from the Fourth R, an evidence-based program for ninth graders, but matches the curriculum and developmental context for eighth graders. Surveys were collected post-intervention from 1012 students within 57 schools randomized to intervention or control conditions. Multivariate multilevel analysis accounted for the nested nature of students within schools. There were significant group differences on three of four outcomes following intervention, including improved knowledge about violence, critical thinking around the impact of violence, and identification of more successful coping strategies. There was no group difference on general acceptance of violence. Overall, students learned relevant information and strategies and were able to apply that knowledge to demonstrate critical thinking, suggesting that adapting an evidence-based approach for use with younger students provided similar benefits. These findings build a case for 2 years of consecutive evidence-based healthy relationships programming in grades 8 and 9, consistent with best practice guidelines.