Benin’s HPV vaccination introduction prioritized 9-year-old girls for routine immunization and expanded coverage to 9–14-year-olds through a multi-age campaign. A demonstration project (2016–2019) in rural and urban districts showed high acceptance and over 90% coverage. Target population estimates combined census data and school enrollment statistics to address gaps for out-of-school girls. The school-based strategy was central, complemented by community outreach. The program faced challenges in target estimation and partner coordination but benefited from strong political support and Gavi funding. This initiative aims to reduce cervical cancer burden and strengthen adolescent immunization platforms.