Racial/ethnic disparities in access to social and environmental supports for physical activity (PA) exist at each level of Bronfenbrenner’s ecological-systems model. African American and Latino youth are less likely to have PA equipment at home, more likely to have access to electronic-media devices, and more likely to attend schools with insufficient PA programming (microsystem). Parents of African American and Latino youth tend to have lower involvement at schools, resulting in fewer opportunities to provide social support for their children’s PA (mesosystem). African American and Latino youth also lack safe places to exercise in their neighborhoods (exosystem) and may experience socioeconomic and cultural barriers to engaging in PA (macrosystem). Yet, there are vast opportunities to intervene—policy approaches, developing school- and family-based programming, and altering the built environment can foster the adoption and maintenance of health-enhancing PA in ethnic-minority youth. This review highlights prominent disparities in PA supports for African American and Latino children and adolescents, as well as current strategies used to reduce disparities in youth PA.