Introduction and Hypothesis <p>Female genital cutting (FGC) remains prevalent in Sierra Leone, yet conventional cross-sectional analyses limit understanding of age-specific risk and long-term temporal trends. We aimed to estimate age-specific prevalence of FGC from 1984 to 2019 and to compare prevalence levels and trends before and after 2013 across selected age cohorts.</p> Methods <p>We conducted a secondary analysis of cross-sectional data from the 2019 Sierra Leone Demographic and Health Survey, which included women aged 15–49&#xa0;years. Participants reported FGC status and age at which FGC occurred. Using respondent age at survey and reported age at FGC, we reconstructed calendar-year–specific prevalence estimates for women aged 15, 20, 25, 30, and 35&#xa0;years from 1984 to 2019. Weighted prevalence before (1984–2013) and after 2013 (2014–2019) was compared, and temporal trends were assessed using survey-weighted linear regression.</p> Results <p>Among 14,644 respondents, the weighted prevalence of FGC was 87.3%. The median age at FGC was 12&#xa0;years (interquartile range 9–15). Weighted prevalence was highest among women aged 35&#xa0;years (94.2%) and lowest among those aged 15&#xa0;years (72.2%), with a marked increase between ages 15 and 20. Significant declines in prevalence were observed across all age groups between the pre- and post-2013 periods, with the largest absolute reduction among 15-year-olds (−15.9%). However, no age group demonstrated a statistically significant change in the rate of decline after 2013.</p> Conclusions <p>Prevalence of FGC in Sierra Leone has declined over time, particularly among younger cohorts, but remains high. Late adolescence and early adulthood represent a critical period of ongoing risk</p>