This entry describes worker centers as new sites of community practice. Worker centers are community-based organizations focused on the needs of low-wage and immigrant workers. This new organizational form emerged most prominently in the United States since the mid-1990s, largely in response to concerns about workplace abuses in low-wage and informal sectors. Drawing on multiple traditions, including labor unions, settlement houses, and ethnic agencies, worker centers offer a hybrid approach to planned change: They support workers organizing for collective action, provide direct services, and advocate for policy change at state and local levels. In the last decade, worker centers have led the efforts to pass legislation protecting domestic workers and helped low-wage workers win millions of dollars in lost or stolen wages from employers. These and other notable examples of U.S. worker centers’ contributions to community practice and social justice will be discussed.