Guymon is a city and county seat of Texas County, in the panhandle of Oklahoma, United States. As of the 2020 census, the city population …Guymon is a city and county seat of Texas County, in the panhandle of Oklahoma, United States. As of the 2020 census, the city population was 12,965, an increase of 13.3% from 11,442 in 2010, and represents more than half of the population of the county, along with being the largest city in the Oklahoma Panhandle. Cattle feedlots, corporate pork farms, and natural gas production dominate its economy, with wind energy production and transmission recently diversifying landowners' farms. Guymon was the only town or city in Oklahoma in 2010 and 2020 in which the majority of the population was Hispanic.