Sulphur Springs is a city in Hopkins County, Texas, in the United States. As of the 2000 census, the city population was 14,551. It is the county seat of Hopkins County. According to the United States Census Bureau, the city has a total area of 21.0square miles (54Square kilometers), of which, 17.9square miles (46Square kilometers) of it is land and 3.2square miles (8.3Square kilometers) of it (15.11%) is water. Sulphur Springs is considered to be part of the humid subtropical area.