Houston is the most populous city in the U.S. state of Texas and the Southern United States. It is the fourth-most populous city in the United States with a population of 2,304,580 at the 2020 census, while the Greater Houston metropolitan area at 7.8 million residents is the fifth-most populous metropolitan area in the nation and second-most populous in Texas. Located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the seat of Harris County. Covering a total area of 640.4 square miles (1,659 km2), Houston is the ninth-most expansive city in the country and the largest whose municipal government is not consolidated with a county, parish, or borough. Although primarily located within Harris County, portions of the city extend into Fort Bend and Montgomery counties. Houston also functions as the southeastern anchor of the Texas Triangle megaregion.