This meta-analysis examines the sex differences in the global prevalence of nonsuicidal self-injury (NSSI) among adolescents. The study included 38 studies with a total of 266,491 participants from 17 countries. The pooled prevalence of NSSI was 17.7%, with a higher prevalence among female adolescents (21.4%) compared to male adolescents (13.7%). NSSI was twice as prevalent among female adolescents in North America (OR, 2.49) and Europe (OR, 2.08) but not in Asia (OR, 1.00). The analysis also found that male adolescents in Asia had a higher prevalence of NSSI compared to other regions. The findings suggest that NSSI is more prevalent among female adolescents globally, with regional variations, and highlight the need for sex- and region-specific interventions to prevent and treat NSSI.This meta-analysis examines the sex differences in the global prevalence of nonsuicidal self-injury (NSSI) among adolescents. The study included 38 studies with a total of 266,491 participants from 17 countries. The pooled prevalence of NSSI was 17.7%, with a higher prevalence among female adolescents (21.4%) compared to male adolescents (13.7%). NSSI was twice as prevalent among female adolescents in North America (OR, 2.49) and Europe (OR, 2.08) but not in Asia (OR, 1.00). The analysis also found that male adolescents in Asia had a higher prevalence of NSSI compared to other regions. The findings suggest that NSSI is more prevalent among female adolescents globally, with regional variations, and highlight the need for sex- and region-specific interventions to prevent and treat NSSI.