This paper presents a participatory research approach to the study of youth activism within a community development and movement-building program. It employs participatory ethnography theory and methods to explore an innovative model of social change for social justice. Building on community youth development and transformative social work perspectives, this study examines the relationship between youth participation in a liberatory education program and the development of an activist identity. This research utilizes a collaborative, community-centric approach to expand social workers' knowledge of community organizing approaches to youth work in terms of (1) how education on oppression and social justice activism support youth development and (2) how youth in an activist program impact their communities. Findings from this study articulate a model of social justice youth development founded in intergenerational collaboration, anti-oppression, community, history, wellness and socio-political development. They indicate that such programming impacts young people's development in terms of their critical consciousness, self-reflexivity, sense of agency, relationships with adults and peers, ability to build alliances and leadership for social justice. Finally, they point to a number ways in which youth activists impact the organizations and communities in which they are engaged, including shaping the policies and practices of youth-serving institutions and the adults who work within them. In terms of implications, this study addresses gaps in knowledge of the impact of youth activism on healthy youth development and contributes to theory-building about the facilitative factors associated with social justice-focused approaches to youth development. It offers us a model of empowerment-based youth services founded in intergenerational relationships, anti-oppressive principles and social change. In practice, these findings indicate that liberatory education and youth activism programs hold enormous potential as avenues of young people's development as engaged citizens. They point to innovative ways to foster youth agency by re-imagining the conditions, policies and practices of service organizations. At the policy level, these findings justify further investment in resources, opportunities and supports that facilitate youth civic engagement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]