Emerging adulthood is a developmental period with high rates of sexual risk behavior. Effective parenting practices can reduce the likelihood of this behavior, but most research on the protective effects of parenting focuses on mothers. Research is needed to assess the role of paternal parenting in regards to their children’s sexual risk behavior, particularly for children of teen mothers, who show a greater likelihood of risky sexual behaviors than those with older mothers. We investigated associations between residential fathers’ parenting processes—communication, disapproval of teen sexual behavior, parental presence, and closeness—during adolescence and sexual risk behaviors reported by their children in emerging adulthood. Using multiple group structural equation modeling with data from 7399 participants at Wave I and Wave III of the National Longitudinal Study of Adolescent to Adult Health (Add Health), we examined whether and how residential fathers’ parenting relates to their children’s sexual risk behavior independent of mothers’ parenting processes, and whether these associations differ across children’s sex and for children of teen and older mothers. We found that adolescents’ perceptions of higher father disapproval of teen sexual behavior predicted lower levels of sexual risk behavior during emerging adulthood with no significant differences across emerging adults’ sex or for children of teen relative to older mothers. Our findings suggest that teens’ relationships with their fathers during adolescence are important for their future sexual health, despite a general understanding of emerging adulthood as a period characterized by independence and separation from parents. Additionally, our results suggest that even though children of teen mothers show greater likelihood of risky sexual behaviors than those of older parents, the processes through which fathers can support teens’ sexual health may be similar.