WorldBeing (formerly CorStone) is an internationally recognized nonprofit organization that conducts innovative in-school wellbeing programs to empower vulnerable and marginalized youth in low- and middle-income countries (LMICs). These programs help youth to re-frame their identities, unleash their potential, and transform their life trajectories. Their programming particularly focuses on gender equality and building the skills of marginalized youth, especially girls, to advocate for their rights, stay in school, and resist early marriage. Kate Sachs Leventhal and Steve Leventhal will share their experiences with WorldBeing and how WorldBeing's vision and inspired programs are changing the lives of youth. WorldBeing helps us understand that mental health concerns among LMIC youth are fueled by systems of entrenched inequities, discrimination, and resource scarcity, exacerbated by a lack of access to services. To improve mental health, WorldBeing believes it is crucial to target improving these systemic injustices and social determinants of poor mental health. WorldBeing’s Youth First and Girls First programs represent one of the first human-centered approaches to youth mental health promotion and prevention, taking injustices and social determinants seriously. The program takes a gender equity lens towards improving mental health and promoting wellbeing. Working from ‘the inside out,’ WorldBeing’s evidence-based wellbeing programs support youth to access their inner wellbeing and resilience, know their rights, and cultivate their power as change agents within their families, schools, and communities. Since 2009, WorldBeing has developed, researched, and conducted wellbeing programs for over 350,000 youth across India, Kenya, and Rwanda. Effectiveness trials of WorldBeing’s programs have provided some of the first evidence demonstrating that fostering wellbeing and resilience amongst vulnerable and marginalized youth significantly improves adolescent mental, emotional, and physical wellbeing; gender equality; and education-related outcomes. Additional impacts include improved school engagement, classroom behaviors, and relationships with teachers, and delayed marriage.