There is now wide recognition that grassroots community organizing is a uniquely necessary approach for contending with the persistent and escalating socioeconomic inequities that manifest as disparities across many societal domains, including housing, safety, education, and mental and physical health. The articles in this special issue report findings from studies designed to increase understanding of community organizing processes and produce actionable knowledge that can enhance these and other similar efforts to create more equitable and just cities and regions. These studies examine a variety of community organizing campaigns, initiatives, and networks in North America, as well as one in Bulgaria, and one in South Africa. These groups are building social power and demanding economic, racial, educational, and environmental justice. In this introductory article, we highlight some of the themes that emerge from this set of studies and make recommendations for future roles that research can play in advancing collective understanding and the practical objectives of grassroots organizing initiatives.