This population-based study evaluates the impact of human papillomavirus (HPV) vaccination programs on cervical cancer incidence across eight countries with established vaccination programs. Using cancer registry data from 2000-2022, we analyzed cervical cancer trends before and after vaccine introduction. Early-adopting countries demonstrated significant reductions in cervical cancer incidence, with the most pronounced decreases observed in cohorts vaccinated before sexual debut. These findings provide compelling real-world evidence supporting the effectiveness of HPV vaccination in cervical cancer prevention and highlight the importance of high vaccination coverage for achieving population-level impact.