Offensive behaviour towards school employees is widespread and involves a number of potentially harmful acts. There is evidence that school employees' experiences of offensive behaviour are shaped by demographic, role and school-based factors that mediate the likelihood of victimisation. However, very few studies have investigated the prevalence and correlates of offensive behaviour against school leaders. This study analysed 13,028 survey responses from the Australia Principal Occupational Health, Safety and Wellbeing survey that were completed between the years 2011 and 2019. The analysis determined the prevalence of bullying, threats of violence and physical violence against government school leaders, the main perpetrators of these offenses and the moderating effects of key socio-demographic factors. Results from the study demonstrated that considerable proportions of Australian government school leaders were subjected to offensive behaviour with an average (pooled) prevalence of 36.2% for bullying, 48.6% for threats of violence and 38.7% for physical violence. School leaders report that students and parents are responsible for most offensive behaviours, but that colleagues also contribute considerably to incidents of bullying. Our findings illustrate that offensive behaviours against Australian school leaders are very high and that particular groups of school leaders are at elevated risk of victimization, especially female school leaders and to a lesser extent assistant principals and those inner or outer regional areas.