Data.gov is the homepage for the U.S. Government's open data. You will find Federal, state, and local data.
This information includes clinical care provider quality information, nationwide health service provider directories, databases of the latest medical and scientific knowledge, consumer product data, community health performance information, and government spending data.
The Journal of Open Psychology Data (JOPD) features peer-reviewed data papers describing psychology datasets with high reuse potential. Data papers may describe data from unpublished work, including replication research, or from papers published previously in a traditional journal.
Annie E. Casey Foundation database includes over 100 indicators of child well-being, including economic status, health, safety, and risk factors on the local community, city, state, and national levels.
openICPSR provides a place for researchers to archive, store, and share their data. All data included in OpenICPSR is free for public use and primarily focuses on behavioral health and social sciences.
Founded in 1968 to understand the problems facing America’s cities and assess the programs of the War on Poverty, the Urban Institute brings decades of objective analysis and expertise to policy debates.
World Bank: Free and open access to global development data