Habitat for Humanity, nonprofit ecumenical Christian organization that enables low-income people to own affordable, livable housing. Headquartered in Americus, Ga., it was founded in 1976 by businessman Millard Fuller and his wife. Using donated materials and funds, those in need of shelter work alongside volunteers to build new homes or rehabilitate older structures. Finished dwellings are sold to participating families at no profit and are financed with no-interest mortgages; mortgage payments are then used to finance more housing. By the early 21st cent. Habitat had built more than 200,000 homes in more than 80 countries.