Well-liked adolescents are more likely than their peers to engage in sexual behaviors, which may place them at higher risk of negative outcomes such as sexually transmitted infections and unwanted pregnancy. Yet, little is known regarding whether peer acceptance in adolescence predicts sexual outcomes in young adulthood. Understanding developmental links between peer acceptance and sexual outcomes will inform theories of how peers affect health and can help identify targets for health promotion efforts. Using longitudinal sociometric data from 1878 participants in the PROSPER study (54% female, 82% White, mean age = 11.79 at baseline), the present research examined the association of adolescent peer acceptance, reported annually from grades 6–11, with adolescent and young adult sexual outcomes. Well-liked adolescents were more likely to have sexual intercourse by age 16. At age 19, well-liked individuals were more likely to have had sexual intercourse but were less likely to be diagnosed with a sexually transmitted infection. For boys but not girls, peer acceptance was linked to having more past year sexual partners in young adulthood. Adolescent peer acceptance was not associated with other young adult sexual outcomes, such as sex without a condom or casual sex. Overall, well-liked adolescents demonstrated healthy sexual development into young adulthood, despite a higher likelihood of sexual initiation early in adolescence. Findings demonstrate the importance of peer acceptance for healthy development into young adulthood and suggest that well-liked adolescents may be appropriate targets for peer-led sexual health education programs.