Urban youth constitute the vanguard of Africa's twinned demographic transformations. Sub-Saharan Africa's youth population growth rate is the highest of any world region (North Africa's rate is also high). In addition, Africa's urban growth rate is the world's highest. Taken together, the need to provide adequate, effective support for urban youth is critical to fostering Africa's development – and its political, social and economic stability. This article is designed to help address this need in two ways. First, it focuses attention on those comprising the overwhelming majority of this population, urban youth who are poor and marginalized. Second, drawing largely on the author's extensive professional experience with African urban youth, the article reviews the major challenges this population faces; considers the programming context for Africa's urban youth; reviews six principles for developing programs for them; provides field-based insights on improving the assessment, monitoring and evaluation of urban youth programming; and suggest ways to enhance the inclusion of female youth in programs. The article concludes with a consideration of the particular challenge of marginalization in meeting the needs of Africa's huge urban youth population, and a call to respond to this challenge with youth-centered policy reforms and investments.