Grand Prairie is a city in the U.S. state of Texas, located in Dallas, Tarrant, and Ellis counties with a small part extending into Johnson county. It …Grand Prairie is a city in the U.S. state of Texas, located in Dallas, Tarrant, and Ellis counties with a small part extending into Johnson county. It is part of the Mid-Cities region in the Dallas–Fort Worth metroplex. It had a population of 175,396 according to the 2010 census, making it the fifteenth most populous city in the state. Remaining the 15th-most populous city in Texas, the 2020 census reported a population of 196,100.