Reno is a city located in Parker County, Texas, United States. As of 2020, its population was 2,878. Not to be confused with Reno, Lamar Coun…Reno is a city located in Parker County, Texas, United States. As of 2020, its population was 2,878. Not to be confused with Reno, Lamar County, Texas. According to the United States Census Bureau, the city has a total area of 12.9 square miles, of which 0.004 square miles, or 0.04%, is water.