The Howland Social Democratic Party (also Social Democrats, Dems, and HSD) is a center-left political party in Howland, one of two major parties in Howland politics. The party was founded in 1939, making it Howland's second-oldest political party. Its primary competitor for political office is the Independence Party of Howland.
The Social Democrats ended nine years in opposition with their victory in the 2009 election, and were returned for a second term at an increased majority at the election in 2012. The party currently holds 30 of the 54 seats in the House of Representatives. Previously, the party was the governing party from 1964–1967, 1976–1979 and 1994–2000.