Enid is the ninth-largest city in the U.S. state of Oklahoma. It is the county seat of Garfield County. As of the 2020 census, the population was 51,308. Enid was founded during the opening of the Cherokee Outlet in the Land Run of 1893, and is named after Enid, a character in Alfred, Lord Tennyson's Idylls of the King. In 1991, the Oklahoma state legislature designated Enid the "purple martin capital of Oklahoma."