Co-occurrence of tobacco use and heavy episodic drinking (HED; 5+ drinks for men and 4+ drinks for women per occasion) is common among young adults; both warrant attention and intervention. In a two-group randomized pilot trial, we investigated whether a Facebook-based smoking cessation intervention addressing both alcohol and tobacco use would increase smoking abstinence and reduce HED compared to a similar intervention addressing only tobacco. Participants were 179 young adults (age 18-25; 49.7% male; 80.4% non-Hispanic white) recruited from Facebook and Instagram who reported smoking 4+ days/week and past-month HED. The Smoking Tobacco and Drinking (STAND) intervention (N = 84) and the Tobacco Status Project (TSP), a tobacco-only intervention (N = 95), both included daily Facebook posts for 90 days and weekly live counseling sessions in private “secret” groups. We verified self-reported 7-day smoking abstinence via remote salivary cotinine tests at 3, 6, and 12 months (with retention at 83%, 66%, and 84%, respectively). Participants self-reported alcohol use. At baseline, the participants averaged 10.4 cigarettes per day (SD = 6.9) and 8.9 HED occasions in the past month (SD = 8.1), with 27.4% in a preparation stage of change for quitting smoking cigarettes. Participants reported significant improvements in cigarette smoking and alcohol use outcomes over time, with no significant differences by condition. At 12 months, intent-to-treat smoking abstinence rates were 3.5% in STAND vs. 0% in TSP (biochemically verified) and 29.4% in STAND vs. 25.5% in TSP (self-reported). Compared to TSP, participants rated the STAND intervention more favorably for supporting health and providing useful information. Adding an alcohol treatment component to a tobacco cessation social media intervention was acceptable and engaging but did not result in significant differences by treatment condition in smoking or alcohol use outcomes. Participants in both conditions reported smoking and drinking less over time, suggesting covariation in behavioral changes.