Objectives Identifying sexual risk patterns associated with HIV/sexually transmitted infections (STI) and early parenthood within population subgroups is critical for targeting risk reduction interventions.Methods Latent Class Analysis (LCA) was used to identify sexual behaviour typologies to predict sexual risk outcomes among 274 (63% female) unmarried, sexually active African-American emerging adults (M age=19.31 years) living in disadvantaged urban neighbourhoods. Participants were enrolled in a larger cross-sectional observational study of risk and protective behaviours. LCA defined membership into discrete risk classes based on reported sex risk behaviours.Results Three groups were identified: The 'low contraception use' risk class (32%) had low rates of condom or other birth control use, moderate rates of sexual initiation before age 16 years, and the highest pregnancy/early parenthood and STI rates. The predominately male 'early sex' risk class (32%) had higher rates of early initiation and multiple partners, risks that were countered by higher contraception and condom use. Both these risk groups showed higher probability to use substances before sex relative to the 'low sex risk' class (36%), which showed low rates on all risk behaviours.Conclusions LCA identified distinct risk clusters that predicted sexual health outcomes and can inform targeted interventions for a minority youth population disproportionately affected by HIV, other STIs, and early parenthood.