This research examines how a student voice experience--Social Justice Youth Summit--developed youth capacities as transformative school leaders. We engaged a youth development framework situated in school- and community-based youth leadership literature to analyze a diverse group of urban youth's experiences and sensemaking of the youth voice experience. Findings illuminate that ways in which youth reciprocally developed individual and collective senses of belonging, competence, and agency toward transformative leadership. Our discussion highlights the importance of urban youth engaging across differences to develop a coalition that addressed multiple systems of oppression manifesting in urban spaces.