High school students are often involved in sexual and dating violence. The bystander approach aims to stop sexual and dating violence from their initial occurrence by promoting social norms supporting victims and tolerating no violence. Recent studies of high school bystander programs report promising evidence of effectiveness in improving attitudes and reducing violence. The theoretical frameworks of the approach and examples of bystander programs are provided. When implementing, administrators are encouraged to commit to fully adopt the program, collaborate with community partners, address cultural relevance, and use policies to create safe and equitable schools for all students.