Bullying, both traditional and cyber, has been associated with several negative outcomes for students, but when bystanders (such as peers or adults) intervene, bullying will often decrease or stop. Teachers are especially important adult bystanders because they are more likely than parents to witness or hear about bullying, especially bullying that occurs in the school setting, but previous research has shown that teachers often do not intervene. Applying the Bystander Intervention Model (notice the event, interpret as an emergency, accept responsibility, know what to do, and act) to bullying in schools may help us understand why teachers may or may not intervene. Via self-report, this study examined associations among affective empathy, perceived bullying seriousness, and each step of the Bystander Intervention Model in Bullying for both traditional bullying and cyber bullying among 150 elementary-high school teachers. Results indicate a positive association between affective empathy and engagement in each step of the Bystander Intervention Model for traditional bullying. Additionally, affective empathy was positively and significantly related to two of the steps (notice the event and take responsibility) for cyber bullying. There was also a positive association between perceived bullying seriousness for two steps of the model (notice the event and interpret as an emergency) for traditional bullying. Implications for teacher involvement in bullying prevention and intervention are discussed.