The Role and Potential of Communities in Population Health Improvement is the summary of a workshop held by the Institute of Medicine Roundtable on Population Health Improvement in April 2014 that featured invited speakers from community groups that have taken steps to improve the health of their communities. Speakers from communities across the United States discussed the potential roles of communities for improving population health. The workshop focused on youth organizing, community organizing or other types of community participation, and partnerships between community and institutional actors. This report explores the roles and potential of the community as leaders, partners, and facilitators in transforming the social and environmental conditions that shape health and well-being at the local level.