INTRODUCTION: Sexual and gender minority (SGM) young adults have higher smoking prevalence than their non-SGM peers. Less is known about differences in smoking characteristics within the SGM community. METHODS: Participants were SGM young adult smokers age 18–25 (N=165, M age=21.8) enrolled in a clinical trial of the Put It Out Project, a Facebook smoking cessation intervention for SGM young adults. Analyses tested differences between 1) sexual orientation groups, and 2) gender identity groups, on the following smoking characteristics: cigarettes/day, daily smoker (yes/no), social smoker (yes/no), years of smoking, number of close friends who smoke (out of 5), age of initiation, age began smoking regularly, time to first cigarette (30 minutes or less/more than 30 minutes), lifetime quit attempts, past-year quit attempts, and stage of change for quitting smoking (precontemplation, contemplation, preparation). RESULTS: Participants were 55% bi/pansexual, 18% gay, 18% lesbian, 9% other (e.g., asexual, queer). The gender identity of the sample was 64% cisgender, 25% transgender, 11% gender non-binary. Lesbian women began smoking at an older age (M=18.0, SD=2.0) than “other” sexual orientation participants (M=15.9, SD=2.6), p