Baytown is a city in Chambers an Harris Counties in the Gulf Coast region of the U.S. state of Texas. Located within the Houston–Sugar Land–Baytown metropolitan area, it lies along both State Highway 146 and Interstate 10. As of the 2000 U.S. Census, Baytown had a total population of 66,430 (though the 2005 census estimate placed the city's population at 68,371) and it is the fourth-largest city within the metropolitan area.