Find out about the list of all Oklahoma (OK) counties in alphabetical order. The U.S state of Oklahoma has 77 counties. Here is the complete list in alphabetical order: A Adair County (OK) Alfalfa County (OK) Atoka County (OK) B Beaver County (OK) Beckham County (OK) Blaine County (OK) Bryan County (OK) C 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) D Delaware County (OK) Dewey County (OK) E Ellis County (OK) G Garfield County (OK) Garvin County (OK) Grady County (OK) Grant County (OK) Greer County (OK) H Harmon County (OK) Harper County (OK) Haskell County (OK) Hughes County (OK) J Jackson County (OK) Jefferson County (OK) Johnston County (OK) K Kay County (OK) Kingfisher County (OK) Kiowa County (OK) L Latimer County (OK) Le Flore County (OK) Lincoln County (OK) Logan County (OK...