Pew Research Center is a nonpartisan fact tank that informs the public about the issues, attitudes and trends shaping the world. They conduct public opinion polling, demographic research, content analysis and other data-driven social science research. They do not take policy positions.
CISER has an extensive data collection with emphasis on labor, political, and social behavior, demography, economics, and health. The collection includes federal and state census files, administrative records, public opinion surveys, economic and social data from national and international organizations, along with studies compiled by individual researchers.
Organization of academic and research organizations that maintains a data repository. Offers reports and statistics across cultures, internationally, arranged by themes such as aging, demographics and race. Some data is for members only.
Trade Associations (support businesses in an industry through conferences, publications, & information) can be sources of data. Sometimes I just Google the word association with the industry I'm interested in. Some data may be for members only.