Although sexual minority stress remains the dominant perspective for understanding disproportionate substance use among lesbian, gay and bisexual (LGB) populations, social norms are among the most predictive and commonly targeted substance use antecedents in other high-risk groups. This scoping review seeks to bring clarity to the body of norms-focused alcohol, tobacco, and other drug (ATOD) research conducted with LGBs over the past 20 years, identify intervention implications, and present priority directions for future research. Fifty-two peer-reviewed studies published between June 1999 and June 2019 were identified from searches of PubMed, PsycInfo, and Medline databases using combinations of terms related to: social norms; sexual orientation or sexual minority status; and, the use of alcohol, tobacco, and other drugs. A far greater number of studies focused on actual ATOD norms than perceived ATOD norms or discrepancies between actual or perceived norms, illuminating the need for additional research focused on these levels of analysis. Taken together, this literature suggests that: (1) perceived ATOD norms are reliable predictors of LGBs' ATOD use; (2) actual ATOD use norms are low among LGBs participating in representative, population-based survey studies; and, (3) LGBs over-estimate the ATOD use of peers. Thus, intervention strategies including personalized normative feedback, psychoeducation, and social branding may hold promise in reducing LGBs substance use. However, additional research is needed to increase our understanding of injunctive ATOD norms, identify meaningful LGB reference groups, elucidate environmental influences on ATOD norms, and examine relationships between stigma experiences, perceived norms, and ATOD use.