Baytown is a city in the U.S. state of Texas, within Harris and Chambers counties. Located in the Houston–The Woodlands–Sugar Land metropolitan statistical area, it lies on the northern side of the Galveston Bay complex near the outlets of the San Jacinto River and Buffalo Bayou. It is the sixth-largest city within this metropolitan area and seventh largest community. Major highways serving the city include State Highway 99, State Highway 146 and Interstate 10.