|City of Sulphur|
|Elevation||16 ft (4.9 m)|
|Area||10.0 sq mi (25.9 km2)|
|- land||10.0 sq mi (26 km2)|
|- water||0.0 sq mi (0 km2), 0%|
|Density||2,043.0 / sq mi (788.8 / km2)|
|- summer (DST)||CDT (UTC-5)|
|ZIP codes||70663, 70665|
Sulphur is named for the sulfur mines, which were excavated in the area in the 1900s. In this area, the German immigrant Herman Frasch invented the "Frasch method" of mining sulfur, pumping hot steam into the ground, liquidizing the mineral, and pumping the liquid to the surface. This greatly facilitated sulfur mining. The elementary school on South Huntington Street in downtown Sulphur is named after Dr. Frasch.
The area was expanded with the addition of the Cities Service (Citgo) oil refinery. The areas of Maplewood and Hollywood were developed to house refinery workers. The Sulphur area is still mostly dependent on the oil refineries and petrochemical plants for employment.
On March 27, 2010, Christopher Lee "Chris" Duncan (born ca. 1962), an insurance agent, became the first Republican elected mayor of Sulphur. In a turnout of 35 percent, Duncan unseated the incumbent Democrat, Ronald M. "Ron" LeLeux (born 1955), 2,555 (54 percent) to 2,156 (46 percent).
The city lies on Interstate 10 between the towns of Vinton and Westlake, approximately 20 miles east of the Texas border. According to the United States Census Bureau, the city has a total area of 10.0 square miles (26 km2), all of it land.
Communities inside Sulphur city limits include, from west to east, old Sulphur, Hollywood, and Maplewood as well as North Sulphur also known as "Portie" (poh-chay) town by natives. Outside of city limits are the communities of Carlyss, Choupique (Shoe-peak), and Moss Lake to the south. The communities of Houston River is north of Town and Mossville is east of Town. Most new development in the city is happening south of town in Carlyss or around Interstate 10.
As of the census of 2000, there were 22,512 people, 7,901 households, and 5,601 families residing in the city. The population density was 2,043.0 people per square mile (788.8/km²). There were 8,665 housing units at an average density of 863.0 per square mile (333.2/km²).
The racial makeup of the city was 93.43% White, 5.41% African American, 0.33% Native American, 0.37% Asian, 0.04% Pacific Islander, 0.35% from other races, and 1.06% from two or more races. Hispanic or Latino of any race were 1.49% of the population.
There were 7,901 households, out of which 34.6% had children under the age of 18 living with them, 53.2% were married couples living together, 13.8% had a female householder with no husband present, and 29.1% were non-families. 24.9% of all households were made up of individuals and 10.1% had someone living alone who was 65 years of age or older. The average household size was 2.56 and the average family size was 3.06.
In the city the population was spread out with 27.1% under the age of 18, 9.5% from 18 to 24, 28.2% from 25 to 44, 21.7% from 45 to 64, and 13.4% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 92.1 males. For every 100 females age 18 and over, there were 88.9 males.
The median income for a household in the city was $38,247, and the median income for a family was $45,455. Males had a median income of $38,235 versus $22,500 for females. The per capita income for the city was $21,615. About 7.5% of families and 9.3% of the population were below the poverty line, including 10.0% of those under age 18 and 11.5% of those age 65 or over.
Most of Sulphur's schools are under the Calcasieu Parish School Board. One high school, Sulphur High School, serves the city along with the Sulphur High Ninth Grade Campus that was completed in 2004. Elementary schools include Frasch, E.K. Key, W.T. Henning, R.W. Vincent, Maplewood, D. S. Perkins, and Vincent Settlement (Carlyss). D.S. Perkins Elementary, one of the areas most struggling schools, is scheduled to close during Christmas Break 2010. All students and teachers are to be transferred to Cypress Cove, a completely new facility located in Carlyss. This would represent a move from one of the more impoverished areas of old Sulphur (North Sulphur AKA "Portie Town"[Portie is pronounced pō-chay]) to one of the wealthier, emerging communities south of town. Middle Schools include Leblanc Middle School, the W.W. Lewis Middle School, and Maplewood (Maplewood offers K-8th grade). There are some private schools in the area as well, including Our Lady's Catholic School on Cypress Street.
Frasch Elementary, W.W. Lewis Middle, and Sulphur High School offer the Spanish Immersion classes in which students take Spanish language as well as core classes totally in Spanish from Kindergarten all the way to eight grade, and Spanish language classes up to Spanish V or VI in High School. The program has been praised by giving children a fluency in the Spanish language as well as an understanding of other cultures (most of the Immersion teachers come from Hispanic countries or are of Hispanic descent) at an early age.
Notable people 
- Marcus R. Clark is a justice of the Louisiana Supreme Court, who was born in Sulphur in 1956.
- Casey Daigle is a baseball pitcher in the Houston Astros organization and husband of softball star Jennie Finch. He graduated from Sulphur High School.
- Grady A. Dugas, M.D. (1923–2007), a 1941 graduate of Sulphur High School, practiced medicine for four decades in Union Parish. He invented an improved wheelchair locks/brake system.
- Michael Durham, born in Sulphur, was an American professional wrestler, better known by his ring name, Johnny Grunge. He has held the ECW and WCW tag titles with his partner, Rocco Rock, who are together known as The Public Enemy.
- Herman Frasch, inventor of the "Frasch Method" of mining sulphur, was head of Union Sulphur Company. Its headquarters were at the Sulphur Mines, a company town just west of present-day Sulphur. Herman Frasch Elementary School is named after him.
- Ronnie Johns is an insurance agent in Sulphur who is an incoming Republican member of the Louisiana State Senate and a member of the state House from 1996 to 2008.
- Claude Kirkpatrick (1917–1997) lived in Sulphur in late 1930s before moving to Jennings, where he served in the Louisiana House of Representatives from 1952-1960.
- Edith Killgore Kirkpatrick (b. 1918), lived in Sulphur in late 1930s before moving to Jennings. She was a member of Louisiana Board of Regents from 1978-1990.
- Alvan Lafargue (1883–1962), Sulphur physician and mayor from 1926–1932
- Janice Lynde of Sulphur was an original cast member of the CBS soap opera The Young and the Restless, having portrayed the character Leslie Brooks. She also appeared on Another World, One Life To Live, and most recently on HBO's Six Feet Under.
- Matt Stevens, Football player: Kansas City Chiefs quarterback, UCLA college football radio analyst
Twin towns 
- Sulphur is twinned with:
- "Louisiana election returns, March 27, 2010". electionresults.sos.louisiana.gov. Retrieved July 7, 2010.
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- "US Board on Geographic Names". United States Geological Survey. 2007-10-25. Retrieved 2008-01-31.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.
- "Justice Marcus R. Clark". Louisiana Supreme Court. Retrieved November 26, 2012.
- "Casey Daigle Stats". Baseball Almanac. Retrieved November 26, 2012.
- "Matthew Anthony Stevens". databaseFootball.com. Retrieved November 26, 2012.