Muskogee County is a county located in the U.S. state of Oklahoma. As of the 2020 census, the population was 66,339. The county seat is Muskogee. The county and city were named for the Muscogee Nation. The official spelling of the name was changed to Muskogee by the post office in 1900. Muskogee County is part of the Muskogee, OK micropolitan statistical area, which is included in the Tulsa-Muskogee-Bartlesville combined statistical area.