Studies on adolescent girls’ vulnerability to sexual coercion in sub-Saharan Africa have focused mainly on individual and partner risk factors, rarely investigating the role the family might play in their vulnerability. This study examined whether household family structure and parental vital status were associated with adolescent girls’ risk of sexual coercion in Rakai, Uganda. Modified Poisson regression was used to estimate relative risk of sexual coercion in the prior twelve months among 1985 unmarried and married adolescent girls aged 15–19 who were participants in the Rakai Community Cohort Study between 2001 and 2008. Among sexually active girls, 11% reported coercion in a given past year. Unexpectedly, living with a single mother was protective against experiencing coercion. 4.1% of never-married girls living with single mothers reported coercion, compared to 7.8% of girls living with biological fathers (adjRR 2.24; 95% CI: 0.98–5.08) and 20% of girls living in step-father households (adjRR 4.73; 95% CI: 1.78–12.53). Ever-married girls whose mothers alone were deceased were more likely to report coercion than those with both parents alive (adjRR 1.56; 95% CI: 1.08–2.30). Protecting adolescent girls from sexual coercion requires prevention approaches which incorporate the family, with particular emphasis on including the men that affect young girls’ sexual development into prevention efforts. Understanding the family dynamics underlying the risk and protective effects of a given household structure might highlight new ways in which to prevent sexual coercion.