BACKGROUND: Females live longer than males, which results in a sex gap in life expectancy. This study examines the contribution of female cancers to this differential by world region and country over the period 1990-2019 with special focus to the 15-69 years age group. METHODS: Cause-specific mortality data for 30 cancers, including 4 female-specific cancers from 238 countries and territories, were retrieved from the Global Burden of Disease Study 2019. Using life table techniques and demographic decomposition analysis, we estimated the contribution of cancer deaths to the sex gap in life expectancy by age and calendar period. RESULTS: At ages 15-69 years, females had a higher life expectancy than males in 2019. Countries with the largest sex gaps or the largest female advantage in life expectancy were in Eastern Europe and Northern Asia, Latin America, and Southern Africa. In contrast, countries with the smallest sex gaps were mainly located in Northern Africa, Northern America, and Northern Europe. The contribution of female-specific cancers to sex gaps in life expectancy were largely negative, ranging from -0.15 years in the Western Pacific to -0.26 years in the Eastern Mediterranean region, implying that the disproportionately higher premature cancer mortality among females contributed to a reduction in the female life expectancy advantage. CONCLUSION: Female-specific cancers are important determinants of sex gaps in life expectancy. Their negative impact on life expectancy at working and reproductive age groups has far-reaching consequences for society. Increasing the availability and access to prevention, screening, timely diagnosis, and effective treatment can reduce this gap.