El Paso County is the westernmost county in the U.S. state of Texas. As of the 2020 census, the population was 865,657, making it the ninth-most populous county in the state of Texas. Its seat is the city of El Paso, the sixth-most populous city in Texas and the 22nd-most populous city in the United States. The county was created in 1850 and later organized i…El Paso County is the westernmost county in the U.S. state of Texas. As of the 2020 census, the population was 865,657, making it the ninth-most populous county in the state of Texas. Its seat is the city of El Paso, the sixth-most populous city in Texas and the 22nd-most populous city in the United States. The county was created in 1850 and later organized in 1871.