| County | FIPS Code | County Seat | Established in | Pop. Density | Population | Area (sq mi) | Area (km2) |
|---|---|---|---|---|---|---|---|
| Adair County | 1 | Stilwell | 1907 | 39.38 | 22,683 | 576 | 1,492 |
| Alfalfa County | 3 | Cherokee | 1907 | 6.51 | 5,642 | 867 | 2,246 |
| Atoka County | 5 | Atoka | 1907 | 14.5 | 14,182 | 978 | 2,533 |
| Beaver County | 7 | Beaver | 1890 | 3.11 | 5,636 | 1,814 | 4,698 |
| Beckham County | 9 | Sayre | 1907 | 24.52 | 22,119 | 902 | 2,336 |
| Blaine County | 11 | Watonga | 1890 | 12.86 | 11,943 | 929 | 2,406 |
| Bryan County | 13 | Durant | 1907 | 46.66 | 42,416 | 909 | 2,354 |
| Caddo County | 15 | Anadarko | 1901 | 23.16 | 29,600 | 1,278 | 3,310 |
| Canadian County | 17 | El Reno | 1901 | 128.38 | 115,541 | 900 | 2,331 |
| Carter County | 19 | Ardmore | 1907 | 57.71 | 47,557 | 824 | 2,134 |
| Cherokee County | 21 | Tahlequah | 1907 | 62.57 | 46,987 | 751 | 1,945 |
| Choctaw County | 23 | Hugo | 1907 | 19.64 | 15,205 | 774 | 2,005 |
| Cimarron County | 25 | Boise City | 1907 | 1.34 | 2,475 | 1,835 | 4,753 |
| Cleveland County | 27 | Norman | 1890 | 477.15 | 255,755 | 536 | 1,388 |
| Coal County | 29 | Coalgate | 1907 | 11.44 | 5,925 | 518 | 1,342 |
| Comanche County | 31 | Lawton | 1907 | 116.09 | 124,098 | 1,069 | 2,769 |
| Cotton County | 33 | Walters | 1912 | 9.72 | 6,193 | 637 | 1,650 |
| Craig County | 35 | Vinita | 1907 | 19.75 | 15,029 | 761 | 1,971 |
| Creek County | 37 | Sapulpa | 1907 | 73.19 | 69,967 | 956 | 2,476 |
| Custer County | 39 | Arapaho | 1891 | 27.83 | 27,469 | 987 | 2,556 |
| Delaware County | 41 | Jay | 1907 | 55.99 | 41,487 | 741 | 1,919 |
| Dewey County | 43 | Taloga | 1892 | 4.81 | 4,810 | 1,000 | 2,590 |
| Ellis County | 45 | Arnett | 1907 | 3.38 | 4,151 | 1,229 | 3,183 |
| Garfield County | 47 | Enid | 1893 | 57.26 | 60,580 | 1,058 | 2,740 |
| Garvin County | 49 | Pauls Valley | 1907 | 34.09 | 27,576 | 809 | 2,095 |
| Grady County | 51 | Chickasha | 1907 | 47.62 | 52,431 | 1,101 | 2,852 |
| Grant County | 53 | Medford | 1892 | 4.52 | 4,527 | 1,001 | 2,593 |
| Greer County | 55 | Mangum | 1896 | 9.76 | 6,239 | 639 | 1,655 |
| Harmon County | 57 | Hollis | 1909 | 5.43 | 2,922 | 538 | 1,393 |
| Harper County | 59 | Buffalo | 1893 | 3.55 | 3,685 | 1,039 | 2,691 |
| Haskell County | 61 | Stigler | 1907 | 22.13 | 12,769 | 577 | 1,494 |
| Hughes County | 63 | Holdenville | 1907 | 17.35 | 14,003 | 807 | 2,090 |
| Jackson County | 65 | Altus | 1907 | 32.93 | 26,446 | 803 | 2,080 |
| Jefferson County | 67 | Waurika | 1907 | 8.53 | 6,472 | 759 | 1,966 |
| Johnston County | 69 | Tishomingo | 1907 | 16.99 | 10,957 | 645 | 1,671 |
| Kay County | 71 | Newkirk | 1895 | 50.67 | 46,562 | 919 | 2,380 |
| Kingfisher County | 73 | Kingfisher | 1907 | 16.65 | 15,034 | 903 | 2,339 |
| Kiowa County | 75 | Hobart | 1901 | 9.31 | 9,446 | 1,015 | 2,629 |
| Latimer County | 77 | Wilburton | 1907 | 15.45 | 11,154 | 722 | 1,870 |
| Le Flore County | 79 | Poteau | 1907 | 31.77 | 50,384 | 1,586 | 4,108 |
| Lincoln County | 81 | Chandler | 1891 | 35.74 | 34,273 | 959 | 2,484 |
| Logan County | 83 | Guthrie | 1891 | 56.17 | 41,848 | 745 | 1,930 |
| Love County | 85 | Marietta | 1907 | 18.3 | 9,423 | 515 | 1,334 |
| Major County | 93 | Fairview | 1909 | 7.87 | 7,527 | 957 | 2,479 |
| Marshall County | 95 | Madill | 1907 | 42.7 | 15,840 | 371 | 961 |
| Mayes County | 97 | Pryor | 1907 | 62.89 | 41,259 | 656 | 1,699 |
| McClain County | 87 | Purcell | 1907 | 60.54 | 34,506 | 570 | 1,476 |
| McCurtain County | 89 | Idabel | 1907 | 17.9 | 33,151 | 1,852 | 4,797 |
| McIntosh County | 91 | Eufaula | 1907 | 32.66 | 20,252 | 620 | 1,606 |
| Murray County | 99 | Sulphur | 1907 | 32.27 | 13,488 | 418 | 1,083 |
| Muskogee County | 101 | Muskogee | 1907 | 87.21 | 70,990 | 814 | 2,108 |
| Noble County | 103 | Perry | 1897 | 15.79 | 11,561 | 732 | 1,896 |
| Nowata County | 105 | Nowata | 1907 | 18.65 | 10,536 | 565 | 1,463 |
| Okfuskee County | 107 | Okemah | 1907 | 19.51 | 12,191 | 625 | 1,619 |
| Oklahoma County | 109 | Oklahoma City | 1891 | 1,013.59 | 718,633 | 709 | 1,836 |
| Okmulgee County | 111 | Okmulgee | 1907 | 57.49 | 40,069 | 697 | 1,805 |
| Osage County | 113 | Pawhuska | 1907 | 21.09 | 47,472 | 2,251 | 5,830 |
| Ottawa County | 115 | Miami | 1907 | 67.62 | 31,848 | 471 | 1,220 |
| Pawnee County | 117 | Pawnee | 1897 | 29.08 | 16,577 | 570 | 1,476 |
| Payne County | 119 | Stillwater | 1890 | 112.76 | 77,350 | 686 | 1,777 |
| Pittsburg County | 121 | McAlester | 1907 | 35.1 | 45,837 | 1,306 | 3,383 |
| Pontotoc County | 123 | Ada | 1907 | 52.07 | 37,492 | 720 | 1,865 |
| Pottawatomie County | 125 | Shawnee | 1891 | 88.12 | 69,442 | 788 | 2,041 |
| Pushmataha County | 127 | Antlers | 1907 | 8.28 | 11,572 | 1,397 | 3,618 |
| Roger Mills County | 129 | Cheyenne | 1895 | 3.19 | 3,647 | 1,142 | 2,958 |
| Rogers County | 131 | Claremore | 1907 | 128.75 | 86,905 | 675 | 1,748 |
| Seminole County | 133 | Wewoka | 1907 | 40.32 | 25,482 | 632 | 1,637 |
| Sequoyah County | 135 | Sallisaw | 1907 | 62.89 | 42,391 | 674 | 1,746 |
| Stephens County | 137 | Duncan | 1907 | 51.37 | 45,048 | 877 | 2,271 |
| Texas County | 139 | Guymon | 1907 | 10.13 | 20,640 | 2,037 | 5,276 |
| Tillman County | 141 | Frederick | 1907 | 9.17 | 7,992 | 872 | 2,258 |
| Tulsa County | 143 | Tulsa | 1907 | 1,058.60 | 603,403 | 570 | 1,476 |
| Wagoner County | 145 | Wagoner | 1907 | 129.81 | 73,085 | 563 | 1,458 |
| Washington County | 147 | Bartlesville | 1907 | 122.24 | 50,976 | 417 | 1,080 |
| Washita County | 149 | Cordell | 1897 | 11.58 | 11,629 | 1,004 | 2,600 |
| Woods County | 151 | Alva | 1893 | 6.9 | 8,878 | 1,287 | 3,333 |
| Woodward County | 153 | Woodward | 1893 | 16.17 | 20,081 | 1,242 | 3,217 |
