Abstract Background: Sexual minority women are at risk for infection with human papillomavirus (HPV), yet little is known about the prevalence of HPV infection among this population. Further, it is not known how the prevalence of HPV infection might vary based on how sexual orientation is measured and operationalized. Methods: We analyzed data from the 2003–2012 National Health and Nutrition Examination Survey (NHANES) among women ages 20–59 (n = 7,132). We examined two dimensions of sexual orientation for each woman (sexual identity and sexual behavior), as well as multiple operational definitions for each dimension (aggregating sexual minority women into one group and disaggregating sexual minority women into subgroups). Weighted logistic regression models determined how HPV infection outcomes (any HPV type, high-risk HPV type, and vaccine-preventable HPV type) varied by dimension. Results: Similar patterns emerged for sexual identity and sexual behavior. In bivariate analyses, HPV infection outcomes were more common among non-heterosexual women compared to heterosexual women (any type: 49.7% vs. 41.1%; high-risk type: 37.0% vs. 27.9%), as well as among women who reported any same-sex partners compared to women who reported only opposite-sex partners (any type: 55.9% vs. 41.0%; high-risk type: 37.7% vs. 28.2%; vaccine-preventable type: 19.1% vs. 14.0%) (P < 0.05). When we disaggregated dimensions of sexual orientation into subgroups, bisexual women and women who reported partners of both sexes had greater odds of HPV infection outcomes (P < 0.05 in bivariate analyses). Multivariate models attenuated several of these differences, though lesbian women and women who reported only same-sex partners had lower odds of most HPV infection outcomes in multivariate analyses (P < 0.05). Conclusions: HPV infection is common among sexual minority women. However, prevalence estimates vary slightly between sexual orientation dimensions and greatly depending on how a dimension is operationally defined. These findings highlight the importance of measuring sexual orientation in various ways and can help inform targeted HPV and cervical cancer prevention efforts for sexual minority women.