Background Gender role non-conforming behaviors are a significant risk factor for school-related violence. The objective of this study is to describe the types, prevalence and correlates of social violence among Thai secondary school students, with a focus on gender role nonconformity. Methods This article uses secondary data from a national study of 2070 secondary school students aged 13-20 years representing Bangkok and all four regions of Thailand. Students were asked about their gender/sexual identity, self-perception of their masculinity or femininity, and experiences of social violence. Correlates of social violence were examined using multivariable logistic regression models. Results Prevalence of social violence victimization was high (57%). Most students considered themselves to be as masculine or as feminine as other members of their sex (82.6%), while 9.1% thought that they were less masculine/less feminine, and 8.3% thought they were more masculine/more feminine. Students who considered themselves less masculine or less feminine than others of their sex (AOR = 1.59, 95% CI: 1.13, 2.25) were more likely to experience social violence, compared to students who considered themselves equally masculine/ feminine. Students who self-identified as lesbian, gay, bisexual or transgender (LGBT) (AOR = 1.37, 95% CI: 1.01, 1.86) were also more likely to experience social violence, compared to students who did not identify as LGBT. However, students who considered PLOS ONE |