Stillwater (Pawnee: Kiicawiʾuusiʾit, Kstiíriwara) is a city in north-central Oklahoma at the intersection of U.S. 177 and State Highway 51. It is the county seat of Payne County, Oklahoma, United States. As of 2012, the city population was estimated to be 46,560, making it the tenth largest city in Oklahoma. Stillwater is the principal city of the Stillwater Micropolitan Statistical Area which had a population of 78,399 according to the 2012 census estimate. Stillwater was part of first Land Run held April 22, 1889, when Oklahoma Territory's Unassigned Lands were opened for settlement. The city charter was adopted on August 24 later that year. Stillwater is home to Oklahoma State University, a branch of Northern Oklahoma College, Meridian Technology Center, and the Oklahoma Department of Career and Technology Education.
Stillwater has a diverse economy with a foundation in aerospace, agribusiness, biotechnology, optoelectronics, printing and publishing, and software and standard manufacturing. The city operates under a council-mayor government system. The city's largest employer is its university. It was one of the 100 top places to live in 2010, according to CNN Money Magazine.