This paper describes the development of Supporting Our Youth, an innovative grassroots program that builds community for lesbian, gay, bisexual, transsexual and transgender youth in Toronto. Hundreds of adults and youth have worked together to develop a broad range of arts, cultural, recreational, and employment training activities, as well as a very popular mentoring and housing program. Initiated in 1997, Supporting Our Youth has been developed according to underlying principles of community development and community building which value broad participation, diverse skills, partnerships, coalition building, and grassroots ownership and direction. As a model, it is transferable to other queer and trans communities, as well as to other marginalized populations.