Female genital mutilation (FGM) is very pervasive in Africa, with significant regional variations in the prevalence of this traditional practice. This study examined the linkages between FGM and multiple sexual partnership in Mali and Sierra Leone – two African countries with a high prevalence of FGM. Data were from the 2018 Mali and 2013 Sierra Leone Demographic and Health Surveys, and the study sample comprised 4750 women from Mali and 16,614 from Sierra Leone. Multilevel logistic regression was used for the data analysis, with reported adjusted odds ratios (aOR) and associated 95% confidence intervals. In Mali, women who had not undergone FGM were less likely to have multiple sexual partners (aOR=0.60, CI=0.38–0.96) compared with those who had undergone FGM. In Sierra Leone, women who had undergone FGM (aOR=1.15, CI=1.02–1.30) were more likely to have multiple sexual partners compared with those who had not undergone FGM. Age, level of education, wealth quintile, sex of household head, community socioeconomic status, mass media exposure, and community literacy level were found to be associated with the likelihood of multiple sexual partnership among women in Mali and Sierra Leone. Comprehensive, age-group-based risk-reduction strategies, such as abstinence education and decision-making skills (assertiveness) training, are needed to reduce girls’ and young women’s engagement in multiple sexual partnerships. Policy interventions, such as anti-FGM legislation and initiatives like the ‘Schooling for the Female Child’ initiative aimed at reducing social inequality among girls and women, might help decrease FGM and the likelihood of health-compromising behaviours like multiple sexual partnership.