Research suggests that sexual minority women (SMW) face elevated HIV risk compared with their heterosexual counterparts. This study examined the association between sexual minority status-defined by identity and behavior-and HIV-related vulnerabilities among heterosexually active low-income women. This analysis used National HIV Behavioral Surveillance data ( = 5542) collected in 2019 from heterosexually active low-income women in 23 U.S. urban areas. We examined sexual minority identity and behavior and a set of substance use, sexual behavior, health and health care, and social determinants of health indicators commonly associated with heightened HIV transmission risk. Log-linked Poisson regression models generated adjusted prevalence ratios and 95% confidence intervals. Among women who reported sexual minority identity (22.2%; = 1231), 34.6% ( = 426) reported past-year sex with only men. Of women who reported past-year sex with both women and men (17.8%; = 985), 18.3% ( = 180) identified as heterosexual. In adjusted models, SMW had significantly higher prevalence of nearly every HIV risk-associated factor examined than their heterosexual counterparts. Risk profiles by identity and behavior were similar. Notably, SMW defined by behavior had similar or higher prevalence of nearly every risk factor than those defined by identity. This study demonstrates disproportionate HIV-related vulnerabilities among SMW compared with their heterosexual counterparts. The findings underscore the importance of measuring multiple dimensions of sexual orientation (identity and behavior), as SMW and their associated risks show important nuances. Implications include tailoring HIV prevention and health promotion interventions to meet the needs of low-income SMW.