Growing evidence documents the gendered costs of war, yet we know comparatively little about which post-conflict policies foster women’s long-run development. This paper estimates the causal effect of UN peacekeeping on women’s human capital in post-war Sierra Leone. Linking geocoded data on UNAMSIL deployment sites to nationally representative demographic surveys, we exploit spatial and cohort variation in exposure to identify the impact of peacekeepers on women’s education. We find that exposure to peacekeeping operations (PKOs) increases women’s education by about 0.8 years, with gains concentrated at the secondary level — including higher secondary attendance and completion. We also document reductions in child marriage and teenage pregnancy. By contrast, we find limited evidence that these improvements operate through broad changes in conflict intensity, local economic recovery as proxied by nightlights, school construction, or development aid. Instead, heterogeneity patterns are most consistent with rehabilitation activities and gender-specific security mechanisms that lowered barriers to girls’ schooling.