K–12 (elementary, middle, and high school) / approximately ages 5–18.

The Olweus Bullying Prevention Program (OBPP) is a multi-tiered, schoolwide system for preventing and reducing bullying at the school, classroom, and individual student levels. The program was developed by Dan Olweus, one of the first researchers to study bullying, and is based on decades of research in this field.

Bullying is treated as a systemic problem of the school environment, so the intervention changes behavioral norms, supervision systems, rules, and individual work with students, rather than being limited to individual lessons.

The program reduces bullying, raises awareness, establishes clear rules, engages adults and parents, and protects victims.

In the classroom, teachers set aside time to discuss bullying and relationships among children: younger grades meet on this weekly, spending a quarter- to a half-hour, while older grades meet less often, once every two weeks, but for longer, 30–40 minutes per session.

Separately, there is individual work with children involved in bullying situations and their parents, and at the level of the broader school community, parent meetings and informational events are organized periodically.

The program's official website states that it has been implemented in thousands of U.S. schools and in more than a dozen countries worldwide, without specifying an exact total number of students.

Originally developed and first implemented in Norway. Since then it has been implemented in more than a dozen countries worldwide and in thousands of U.S. schools. An exact list of countries or a current number of implementation regions is not specified on verified pages.

Program materials exist in at least five languages: English, Norwegian (the original), German, Dutch, and Spanish (Spanish-language materials are included in the standard classroom lesson kit). The official U.S. provider confirms that materials are available in other languages as well, but recommends checking the program's website for the specific list.

The program is included in the Blueprints for Healthy Youth Development registry with Promising status — confirmed multiple times and remaining the program's current status.

Large-scale studies of the program in Norway: six large-scale evaluations were conducted, covering more than 30,000 students from more than 300 schools. Among students in grades 4–7, results consistently showed a positive effect: the typical reduction in bullying problems was 35–50% after eight months of program implementation.