Whilst school violence is a major public concern and a focus of educational reforms both in the USA and South Korea, few studies have comparatively examined the rates of school violence and school factors associated with them. Analysing nationally-representative data from eighth graders, their mathematics teachers and principals in 150 South Korean schools and in 216 US schools, the authors found that: (1) the rates of school violence are higher in the US than South Korea, (2) student-reported violence rates are not associated with school-reported violence rates in both nations and (3) South Korean schools with academic tracking and low-achieving US schools are more likely to have higher rates of school violence. Policy and practical implications of these findings are discussed.