ABSTRACT Sexual and gender minority (SGM) young adults (those who identify with a sexual orientation that is non- heterosexual such as gay, lesbian, or bisexual; or those who have a gender identity different from the sex assigned to them at birth) are disproportionately affected by tobacco use and associated health conditions; yet they face significant barriers to treatment participation and lower levels of satisfaction with treatment than others. Despite consensus that SGMs fare better when programs are tailored to address their specific needs, there is an extreme lack of such services available. Social media offer phenomenal opportunity to engage young people in intervention to treat tobacco use. Our group has developed the Facebook Tobacco Status Project (TSP), a stage-matched smoking cessation intervention for young adults based on US Clinical Practice Guidelines for smoking cessation, with evidence of short-term efficacy with young adult smokers. A culturally- tailored intervention may improve quit rates with SGM young adults. With pilot funds from UC San Francisco, our team has conducted mixed-methods formative work with SGM young adult smokers to inform the development of the Put It Out Project (POP) - an adaptation of TSP for SGM young adults. This project will bring together an interdisciplinary team with experience in the areas of SGM tobacco use, social media intervention, social media analytics, and clinical trials testing interventions for tobacco use, to evaluate feasibility and efficacy of POP. We will evaluate POP against the original TSP intervention in a randomized design with 120 SGM young adults throughout the United States who have smoked at least 100 cigarettes in their lifetimes and smoke cigarettes on 4 or more days per week. Participants will be recruited online and randomized to either POP with tailored content or the original TSP intervention. Both conditions will assign SGM participants to a private Facebook group and deliver a 90-day intervention including Facebook postings and weekly ?The Dr. Is In? sessions with a trained counselor to guide group sessions. Two historical control conditions from our current clinical trial include assignment to TSP with non-SGM participants and referral to the NCI smokefree.gov program. All participants will complete baseline, 3-, and 6-month follow-up assessments online. Primary outcome will be biochemically-verified 7-day point prevalence abstinence from tobacco. Within the TSP-SGM and TSP conditions, analyses will examine features of Facebook posts and user communications that are most strongly related to tobacco outcomes. This is the first project involving the target community to use Facebook to treat tobacco dependence among SGM young adults. Results will be used to design a clinical trial powered to detect significant effects across groups, thereby determining optimal intervention for a priority population.