Bartlesville is a city mostly in Washington County in the U.S. state of Oklahoma. The population was 35,750 at the 2010 census, with a 2015 estimate of 36,595 according to the U.S. Census Bureau. Bartlesville is 47 miles north of Tulsa and 18 miles south of the Kansas border. It is the county seat of Washington County. The Caney River runs through Bartlesville.Bartlesville is the primary city of the Bartlesville Micropolitan area, which consists of Washington County and had a population of 52,021 in 2015. A small portion of the city is in Osage County, which is part of the Tulsa metropolitan area. The city is also part of the Tulsa Combined Statistical Area, with a population of 1,151,172 in 2015.Bartlesville is notable as the longtime home of Phillips Petroleum Company. Frank Phillips founded Phillips Petroleum in Bartlesville in 1905 when the area was still an Indian Territory.