Sulphur is a city in Murray County, Oklahoma, United States. The population was 4,794 at the 2000 census. It is the county seat of Murray County. As of the census of 2000, there were 4,794 people, 1,877 households, and 1,244 families residing in the city. The population density was 703.1 people per square mile (271.4/km²). There were 2,220 housing units at an average density of 325.6 per square mile (125.7/km²). The racial makeup of the city was 79.45% White, 1.36% African American, 12.72% Native American, 0.38% Asian, 0.04% Pacific Islander, 1.52% from other races, and 4.53% from two or more races. Hispanic or Latino of any race were 4.80% of the population.