BACKGROUND. Despite the proliferation of evidence-based digital mental health programs for young people, low uptake and inconsistent implementation precludes them from benefiting youth at scale. Identifying effective implementation strategies for evidence-based supports is especially critical in regions where treatment access is lowest due to mental health provider shortages. Objective. The goal of this academic-community partnership, funded by the City of San Antonio Metropolitan Health District, was to culturally adapt, disseminate, and gauge the acceptability and utility of an evidence-based digital mental health platform—Project YES (www.schleiderlab.org/yes)—among English- and Spanish-speaking youth living in south Texas. METHODS. Project YES is an open-access, anonymous platform containing three evidence-based, self-guided interventions for youth mental health. Project YES was culturally adapted via focus groups and co-design sessions with San Antonio youth with lived experience of depression and anxiety; translated into Spanish; and disseminated throughout San Antonio, Texas, via community and school partnerships. RESULTS. During the project period (April 2021–December 2021), 1,801 San Antonio youth began and 894 completed a 30-minute, single-session intervention within Project YES (ages 11-17; 39.9% male, 53.4% female, 0.2% intersex; 82.0% Hispanic, 4.3% non-Hispanic white, 6.3% Black, 1.6% Asian, 5.2% other). This completion rate (49.6%) surpassed those previously observed for Project YES (e.g., 34% when disseminated via social media). San Antonio youth rated Project YES as highly acceptable across all metrics, both in English and Spanish. Additionally, youth who completed Project YES - ENGLISH reported significant improvements in hopelessness (d = 0.33), self-hate (d = 0.27), and perceived agency (d = 0.25), from pre- to post-intervention, and teens who completed Project YES - SPANISH reported improvements in self-hate (d = 0.37) from pre- to post-intervention. CONCLUSIONS. Results indicate that Project YES—an open-access, free, anonymous online single-session intervention (SSI) platform—is an acceptable, accessible, and applicable mental health support for English- and Spanish-speaking San Antonio youth.