AbstractIntroductionSexual and gender minority (SGM) nicotine and tobacco use disparities are well-documented among youth and young adults (YYA), and despite decades of prevention efforts, these disparities stubbornly persist. To better understand tobacco use disparities and craft tailored interventions, tobacco use patterns must be assessed in a contemporary sample of YYA across lines of sexual and gender identity, sex assigned at birth, and tobacco product types.Aims and MethodsData were from an online survey of a diverse sample of emerging adult tobacco users (ages 18–29;N= 1491) in California, United States (2020–2021). Participants were recruited from various online and in-person locations. Bivariate and adjusted models assessed differences in four nicotine and tobacco use outcomes (past 30-day use of cigarettes, e-cigarettes, other tobacco products, and multiple tobacco product types) across six groups: Cisgender heterosexual males, cisgender heterosexual females, cisgender sexual minority (SM) males, cisgender SM females, transfeminine participants, and transmasculine participants.ResultsCompared to cisgender heterosexual males, both transfeminine (OR = 2.25, 95% confidence intervals (CI) = 1.29 to 4.05) and transmasculine (OR = 1.85, 95% CI = 1.32 to 2.80) participants had higher odds of using cigarettes. Few differences were noted between groups in use of e-cigarettes. Cisgender heterosexual males had higher odds of other tobacco product use, compared to most other groups (eg, cisgender SM males: OR = 0.57, 95% CI = 0.37 to 0.87). Transmasculine participants had higher odds of multiple product use, compared to cisgender heterosexual females. Among multiple product users, transfeminine participants had the highest prevalence of using all three individual product types (35.6%).ConclusionsResults highlight the need for different tobacco control approaches across sexual and gender identities, sex assigned at birth, and nicotine and tobacco products.ImplicationsSGM nicotine and tobacco use disparities remain entrenched, despite concerted efforts to reduce them. The SGM population is heterogeneous and different SGM subgroups may have different needs. This study assessed, among young adult nicotine and tobacco users in California, U.S. patterns of tobacco use across sexual and gender identities, sex assigned at birth, as well as specific tobacco products used—a necessity to craft tailored tobacco control measures. We found patterns of nicotine and tobacco product use across several of these characteristics, highlighting how different prevention and cessation interventions may be needed to meaningfully address SGM nicotine and tobacco use disparities.