Washington County, Oklahoma

Washington County
Washington County
County
	Old Washington County Courthouse in Bartlesville
	Location within the U.S. state of Oklahoma
	Oklahoma's location within the U.S.
	Coordinates: 36°44′50″N 95°58′50″W / 36.747206°N 95.980597°W
Country	United States
State	Oklahoma
Founded	1907
Named for	George Washington
Seat	Bartlesville
Largest city	Bartlesville
Area
• Total	424 sq mi (1,100 km2)
• Land	415 sq mi (1,070 km2)
• Water	8.8 sq mi (23 km2) 2.1%
Population (2020)
• Total	52,455
• Density	120/sq mi (48/km2)
Congressional district	1st
Website	www.countycourthouse.org

Washington County is a county located in the northeastern part of the U.S. state of Oklahoma. As of the 2020 census, the population was 52,455.^[1] Its county seat is Bartlesville.^[2] Named for President George Washington, it is the smallest county in Oklahoma in total area,^[3] adjacent to the largest county in Oklahoma, Osage County.

Washington County comprises the Bartlesville, OK micropolitan statistical area, which is also included in the Tulsa-Muskogee-Bartlesville, OK combined statistical area. It is located along the border with Kansas.

^ Cite error: The named reference census was invoked but never defined (see the help page).
^ "Find a County". National Association of Counties. Retrieved June 7, 2011.
^ Jon D. May, "Washington County." Encyclopedia of Oklahoma History and Culture.