| City/Town | Area Code | Zip Code | County | Code |
| Cache | 405 | 73527 | Comanche | 40031 |
| Caddo | 405 | 74729 | Bryan | 40013 |
| Calera | 405 | 74730 | Bryan | 40013 |
| Calumet | 405 | 73014 | Canadian | 40017 |
| Calvin | 405 | 74531 | Hughes | 40063 |
| Camargo | 405 | 73835 | Dewey | 40043 |
| Cameron | 918 | 74932 | LeFlore | 40079 |
| Canadian | 918 | 74425 | Pittsburg | 40121 |
| Caney | 405 | 74533 | Atoka | 40005 |
| Canton | 405 | 73724 | Blaine | 40011 |
| Canute | 405 | 73626 | Washita | 40149 |
| Capron | 405 | 73725 | Woods | 40151 |
| Cardin | 918 | 74335 | Ottawa | 40115 |
| Carmen | 405 | 73726 | Alfalfa | 40003 |
| Carnegie | 405 | 73015 | Caddo | 40015 |
| Carney | 405 | 74832 | Lincoln | 40081 |
| Carrier | 405 | 73727 | Garfield | 40047 |
| Carter | 405 | 73627 | Beckham | 40009 |
| Cartersville | 918 | 74941 | Haskell | 40061 |
| Cartwright | 405 | 74731 | Bryan | 40013 |
| Cashion | 405 | 73016 | Kingfisher | 40073 |
| Castle | 918 | 74833 | Okfuskee | 40107 |
| Catoosa | 918 | 74015 | Rogers | 40131 |
| Cement | 405 | 73017 | Caddo | 40015 |
| Centrahoma | 405 | 74534 | Coal | 40029 |
| Chandler | 405 | 74834 | Lincoln | 40081 |
| Chattanooga | 405 | 73528 | Comanche | 40031 |
| Checotah | 918 | 74426 | McIntosh | 40091 |
| Chelsea | 918 | 74016 | Rogers | 40131 |
| Cherokee | 405 | 73728 | Alfalfa | 40003 |
| Chester | 405 | 73838 | Major | 40093 |
| Cheyenne | 405 | 73628 | Roger Mills | 40129 |
| Chickasha | 405 | 73018 | Grady | 40051 |
| 73023 | ||||
| Chilocco | 405 | 74647 | Kay | 40071 |
| Choctaw | 405 | 73020 | Oklahoma | 40109 |
| Chouteau | 918 | 74337 | Mayes | 40097 |
| Claremore | 918 | 74017 | Rogers | 40131 |
| 74018 | ||||
| Clarita | 405 | 74535 | Coal | 40029 |
| Clayton | 918 | 74536 | Pushmataha | 40127 |
| Clearview | 405 | 74835 | Okfuskee | 40107 |
| Clebit | 405 | 74728 | McCurtain | 40089 |
| Clemscot | 405 | 73437 | Carter | 40019 |
| Cleo Spnngs | 405 | 73729 | Major | 40093 |
| Cleveland | 918 | 74020 | Pawnee | 40117 |
| Clinton | 405 | 73601 | Custer | 40039 |
| Cloud Chief | 405 | 73632 | Washita | 40149 |
| Cloudy | 405 | 74562 | Pushmataha | 40127 |
| Coalgate | 405 | 74538 | Coal | 40029 |
| Colbert | 405 | 74733 | Bryan | 40013 |
| Colcord | 918 | 74338 | Delaware | 40041 |
| Coleman | 405 | 73432 | Johnston | 40069 |
| College | 405 | 74074 | Payne | 40119 |
| Collinsville | 918 | 74021 | Tulsa | 40143 |
| Colony | 405 | 73021 | Washita | 40149 |
| Comanche | 405 | 73529 | Stephens | 40137 |
| Commerce | 918 | 74339 | Ottawa | 40115 |
| Concho | 405 | 73022 | Canadian | 40017 |
| Connerville | 405 | 74836 | Johnston | 40069 |
| Cook | 405 | 73100 | Oklahoma | 40109 |
| Cookson | 918 | 74427 | Cherokee | 40021 |
| Cooperton | 405 | 73564 | Kiowa | 40075 |
| Copan | 918 | 74022 | Washington | 40147 |
| Cordell | 405 | 73632 | Washita | 40149 |
| Corn | 405 | 73024 | Washita | 40149 |
| Council Hill | 918 | 74428 | Muskogee | 40101 |
| Countyline | 405 | 73025 | Stephens | 40137 |
| Covington | 405 | 73730 | Garfield | 40047 |
| Coweta | 918 | 74429 | Wagoner | 40145 |
| Cox city | 405 | 73082 | Grady | 40051 |
| Coyle | 405 | 73027 | Logan | 40083 |
| Crawford | 405 | 73638 | Roger Mills | 40129 |
| Crescent | 405 | 73028 | Logan | 40083 |
| Cromwell | 405 | 74837 | Seminole | 40133 |
| Crowder | 918 | 74430 | Pittsburg | 40121 |
| Cumberland | 405 | 73446 | Marshall | 40095 |
| Cushing | 918 | 74023 | Payne | 40119 |
| Custer City | 405 | 73639 | Custer | 40039 |
| Cyril | 405 | 73029 | Caddo | 40015 |