Keller is a city in Tarrant County, Texas, United States, in the Dallas–Fort Worth metroplex. According to the 2020 census, the city's population is 45,776, making Keller the 80th most populated city in Texas. The most recent population estimate, as of July 1, 2021, is 45,397.

Tarrant County is a county located in the U.S. state of Texas with a 2020 U.S. census population of 2,110,640, making it the third-most populous county in Texas and the 15th-most populous in the United States. Its county seat is Fort Worth. Tarrant County, one of 26 counties created out of the Peters Colony, was established in 1849 and organized the next year. It is named after Edward H. Tarrant, a lawyer, politician, and militia leader.