The state of Oklahoma has 77 counties in total. Beaver County is the oldest (founded in 1890), while Cotton County is the youngest (established in 1912).

Oklahoma County is the most populous, with a population of 718,633. Osage County (5,830 km2) has the most land area, while Marshall County has the smallest (961 km2).

Please find a list of all Oklahoma counties sorted alphabetically below.

• Adair County, OK
• Alfalfa County, OK
• Atoka County, OK
• Beaver County, OK
• Beckman County, OK
• Blaine County, OK
• Bryan County, OK
• Caddo County, OK
• Canadian County, OK
• Carter County, OK
• Cherokee County, OK
• Choctaw County, OK
• Cimarron County, OK
• Cleveland County, OK
• Coal County, OK
• Comanche County, OK
• Cotton County, OK
• Craig County, OK
• Creek County, OK
• Custer County, OK
• Delaware County, OK
• Dewey County, OK
• Ellis County, OK
• Garfield County, OK
• Garvin County, OK
• Grady County, OK
• Grant County, OK
• Greer County, OK
• Harmon County, OK
• Harper County, OK
• Haskell County, OK
• Hughes County, OK
• Jackson County, OK
• Jefferson County, OK
• Johnson County, OK
• Kay County, OK
• Kingfisher County, OK
• Kiowa County, OK
• Latimer County, OK
• Le Flore County, OK
• Lincoln County, OK
• Logan County, OK
• Love County, OK
• Major County, OK
• Marshall County, OK
• Mayes County, OK
• McClain County, OK
• McCurtain County, OK
• McIntosh County, OK
• Murray County, OK
• Muskogee County, OK
• Noble County, OK
• Nowata County, OK
• Okfuskee County, OK
• Oklahoma County, OK
• Okmulgee County, OK
• Osage County, OK
• Ottawa County, OK
• Pawnee County, OK
• Payne County, OK
• Pittsburg County, OK
• Pontotoc County, OK
• Pottawatomie County, OK
• Pushmataha County, OK
• Roger Mills County, OK
• Rogers County, OK
• Seminole County, OK
• Sequoyah County, OK
• Stephens County, OK
• Texas County, OK
• Tillman County, OK
• Tusla County, OK
• Wagoner County, OK
• Washington County, OK
• Washita County, OK
• Woods County, OK
• Woodward County, OK