| CHU | - | Chuathbaluk Airport | Chuathbaluk | |
| LUK | KLUK | Cincinnati Municipal Airport - Lunken Field | Cincinnati | |
| RCP | - | Cinder Park Airport | Cinder Park | |
| IRC | SCIR | Circle City Airport | Circle | |
| - | KJVY | Clark Regional Airport | Jeffersonville | |
| CLP | - | Clarks Point Airport | Clarks Point | |
| CAO | KCAO | Clayton Municipal Airpark | Clayton | |
| CLK | KCLK | Clinton Regional Airport | Clinton | |
| CVN | KCVN | Clovis Municipal Airport | Clovis | |
| EWN | KEWN | Coastal Carolina Regional Airport | New Bern | |
| CFA | - | Coffee Point Airport | Coffee Point | |
| KCC | - | Coffman Cove Sea Plane Base | Coffman Cove | |
| CBK | KCBK | Colby Municipal Airport | Colby | |
| CDB | PACD | Cold Bay Airport | Cold Bay | |
| CXF | - | Coldfoot Airport | Coldfoot | |
| DET | KDET | Coleman A. Young Municipal Airport | Detroit | |
| - | KAAO | Colonel James Jabara Airport | Wichita | |
| HCC | - | Columbia County Airport | Hudson | |
| COU | KCOU | Columbia Regional Airport | Columbia | |
| CSG | KCSG | Columbus Airport | Columbus | |
| CLU | KBAK | Columbus Municipal Airport | Columbus | |
| CON | KCON | Concord Municipal Airport | Concord | |
| USA | KJQF | Concord Regional Airport | Concord | |
| CTX | - | Cortland County Airport | Cortland | |
| CVO | KCVO | Corvallis Municipal Airport | Corvallis | |
| CTW | - | Cottonwood Airport | Cottonwood | |
| VCT | KVCT | County-Foster Airport | Victoria | |
| CGA | - | Craig Seaplane Base | Craig | |
| BUB | KBUB | Cram Field | Burwell | |
| LMT | KLMT | Crater Lake Klamath Regional Airport | Klamath Falls | |
| CKD | - | Crooked Creek Airport | Crooked Creek | |
| BRD | KBRD | Crow Wing County Airport | Brainerd | |
| CYE | - | Crystal Lake Airport | Crystal Lake | |
| VHN | KVHN | Culberson County Airport | Van Horn | |
| - | KCJR | Culpeper Regional Airport | Culpeper | |
| CTB | KCTB | Cut Bank Municipal Airport | Cut Bank | |
| CGF | KCGF | Cuyahoga County Airport | Cleveland | |
| RBD | KRBD | Dallas Executive Airport | Dallas | |
| DXR | KDXR | Danbury Municipal Airport | Danbury | |
| DNL | KDNL | Daniel Field | Augusta | |
| DAN | KDAN | Danville Regional Airport | Danville | |
| MEO | KMQI | Dare County Regional Airport | Manteo | |
| DVN | KDVN | Davenport Airport | Davenport | |
| DWH | KDWH | David Wayne Hooks Memorial Airport | Houston | |
| OWB | KOWB | Daviess County Airport | Owensboro | |
| DMA | KDMA | Davis Monthan Air Force Base | Tucson | |
| GDV | KGDV | Dawson Community Airport | Glendive | |
| DAB | KDAB | Daytona Beach International Airport | Daytona Beach | |
| DEC | KDEC | Decatur Airport | Decatur | |
| DHB | - | Deer Harbor Sea Plane Base | Orcas Island | |