In the least healthy county of Ohio, one primary care doctor serves every 15,000 residents, almost one-quarter of the population faces severe housing problems, and barely one-third graduates high school on time. The healthiest Ohio county, by contrast, has one primary care physician per 750 people, 7 percent of the population faces severe housing problems and 83 percent have attended college. Varying rates of opioid addiction are equally dramatic. Such disparities are echoed in every US state and across the globe, with local conditions producing vastly different life expectancies. Access to clinical care and health insurance explain some of the differential, but income inequality, economic opportunities, the built environment, pollution, violence, and community supports account for more. From Louisville, Kentucky, and Santa Monica, California, to Santiago, Chile, and Kigali, Rwanda, communities are tackling local health issues with innovative, cross-disciplinary revitalization strategies. What is a healthy community and how do we build them?