Strengthening communities and the roles of individuals in building community life can help prevent disease and disability and expand resources for promoting social justice. This chapter discusses addressing social injustice through community transformation and the roles that public health workers can play in this process by developing authentic partnerships with communities, recognizing and building on community strengths, and using public health approaches that address the root causes of health disparities. Communities can be strengthened in their capacity to address their health problems and the root causes of these problems. Public health workers need new skill sets and intervention strategies to assist communities in meeting the challenges that they face. A text box discusses strengthening communities in low- and middle-income countries. A second text box describes the work of a community-based foundation (the MetroWest Health Foundation) in addressing social injustice at the local level.