Missouri City is a city in the U.S. state of Texas, within the Houston–The Woodlands–Sugar Land metropolitan area. The city is mostly in Fort …Missouri City is a city in the U.S. state of Texas, within the Houston–The Woodlands–Sugar Land metropolitan area. The city is mostly in Fort Bend County, with a small portion in Harris County. As of the 2020 census, the city had a population of 74,259, an increase over the figure of 67,358 tabulated in 2010.