Houston is the most populous city in the U.S. state of Texas, the fourth most populous city in the United States, the most populous city in the Southern United States, as well as the sixth most populous in North America, with an estimated 2018 population of 2,325,502. Located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the seat of Harris County and the principal city of the Greater Houston metropolitan area, which is the fifth most populous metropolitan statistical area in the United States and the second most populous in Texas after the Dallas-Fort Worth metroplex, with a population of 6,997,384 in 2018.
Comprising a total area of 637.4 square miles (1,651 km2), Houston is the eighth most expansive city in the United States (including consolidated city-counties). It is the largest city in the United States by total area, whose government is not consolidated with that of a county, parish or borough. Though primarily in Harris County, small portions of the city extend into Fort Bend and Montgomery counties, bordering other principal communities of Greater Houston such as Sugar Land and The Woodlands.