Health disparities related to sexual orientation and gender identity exist across multiple outcomes. Scholarship has begun to evaluate whether structural stigma-ie, societal-level conditions, cultural norms, and institutional policies that constrain opportunities, resources, and wellbeing-contributes to health burdens among LGBTQ+ individuals. We conducted a comprehensive review of quantitative studies examining this hypothesis. We found 98 articles that linked objective (ie, non-self-reported) measures of structural stigma to mental (n=57), behavioural (ie, substance use; n=27; HIV/AIDS or sexually transmitted infection; n=20), and physical (n=20) health outcomes. There was generally consistent evidence that structural stigma increases risk of poor health among LGBTQ+ individuals. Several methodological strengths were identified, including the use of multiple measures (eg, laws or policies [59%, 58 of 98]), designs (eg, quasi-experiments [21%, 21 of 98]), and samples (eg, probability-based [56%, 55 of 98]). However, important gaps exist. Just over half of studies included area-level covariates or non-LGBTQ+ comparison groups, which are necessary to address alternative explanations for the observed associations. Additionally, while studies (n=90) have begun to identify candidate mechanisms, only nine (10%) formally tested mediation. We offer suggestions for future research to advance this literature, which has implications not only for the identification of structural determinants of LGBTQ+ health but also for the development of public health interventions that reduce LGBTQ+ health disparities.