Bartlesville is a city located in northeastern Oklahoma, United States. It is the county seat of Washington County and has a population of approximately 35,750 people. The city is known for its historic downtown area, which features several buildings listed on the National Register of Historic Places. Bartlesville is also home to several cultural and recreational attractions, including the Price Tower Arts Center, which was designed by renowned architect Frank Lloyd Wright. The city is also the corporate headquarters of Phillips 66, a multinational energy company.