Bath is a city in Sagadahoc County, Maine, in the United States. The population was 8,514 at the 2010 census. It is the county seat of Sagadahoc County. Bath is a port of entry with a good harbor formed by the Kennebec River estuary. The city is popular with tourists, many drawn by its 19th-century architecture. It is home to the Bath Iron Works and Heritage Days Festival, held annually on the Fourth of July weekend. Bath is part of the Portland–South Portland–Biddeford, Maine metropolitan statistical area.