AbstractObjectiveTo explore profiles of family communication about sex, demographic predictors of membership in these profiles, and their relationship to outcomes associated with sexual activity.BackgroundFamily communication about sex is protective against risky sexual behaviors. However, most research has focused solely on communication with parents. Emerging research suggests that extended family, such as aunts, uncles, cousins, and siblings, may also contribute to sexual socialization. This study assessed patterns of adolescents' communication with parents and extended family across three areas of communication about sex: protection, risk, and relationships.MethodThis research used cross‐sectional data from 844 adolescents (54% Latinx, 17% Black, 56% female) and conducted latent profile analysis.ResultsIn the resulting four profiles, adolescents reported talking with no one, primarily parents, everyone, or extended family only. Race and immigration status predicted profile membership. There was a significant relationship between having engaged in sex and profile membership but no significant associations with risk behaviors.ConclusionThis study provides evidence that youth communicate at different frequencies and sometimes in different ways with parents and extended family. Some patterns of communication are related to whether youth are sexually active.ImplicationsPractitioners should consider inclusion of both parents and extended family in supporting adolescent sexual socialization and health, and interventions should account for extended family as part of adolescents' family ecology. Future research and intervention might consider how to engage the large number of students who report no talk with any family member about sex.