Houston is in the United States.
Houston ( [ ˈhjuːstən ] ) is the most populous city in the state of Texas and the fourth-most populous city in the United States . With a census-estimated 2014 population of 2.239 million within an area of 667 sqmi , it is also the largest city in the southern United States and the seat of Harris County . Located in Southeast Texas near the Gulf of Mexico , it is the principal city of the Greater Houston metro area , which is the fifth-most populated MSA in the United States . United States . The capital is Washington , D.C. , and the largest city is New York City ; nine other major metropolitan areas -- each with at least 4.5 million inhabitants and the largest having more than 13 million people -- are Los Angeles , Chicago , Dallas , Houston , Philadelphia , Miami , Atlanta , Boston , and San Francisco .