| 1 | CIL | Cecil Aviation Ltd. | Callsign: Cecil, Ceased operations. ICAO callsign changed from Cecil | GB | AVCODES |
| 2 | CIL | Cecil Aviation Ltd. | Callsign: Cil, ICAO callsign changed from Cil | GB | AVCODES |
| 3 | CIL | CIAF Leasing | IATA: CF, Callsign: CIAF Leasing, | ET | AVCODES |
| 4 | CIL | Cecil Aviation | | | ICAO1 |
| 5 | CIL | Louisville and Nashville R.R. Co. | eliminated 1/1983 | | NAKINA |
| 6 | CIL | Louisville and Nashville R.R. Co. (Chicago, Indianapolis & Louisville) | 1/1975-1/1980 | | NAKINA |
| 7 | CIL | Chicago, Indianapolis & Louisville Ry. Co. (Monon R.R.) | 4/1938-10/1966 | | NAKINA |
| 8 | CIL | Chicago, Indianapolis & Louisville Ry. Co. (Monon R.R.) | 4/38-10/66 | | NRHS |
| 9 | CIL | Louisville and Nashville R.R. Co. (Chicago, Indianapolis & Louisville) | 1/75-1/80 | | NRHS |
| 10 | CIL | Louisville and Nashville R.R. Co. | eliminated 1/83 | | NRHS |
| 11 | CIL | LOUISVIULLE & NASHVILLE RAILROAD [CHICAGO, INDIANAPOLIS & LOUISVILLE RWY. (MONON RAILROAD)] | | | PWRC |
| 12 | CIL | Chicago, Indianapolis & Louisville Ry. Co. (Monon R.R.) | | USA | TRAFFIC |
| 13 | CILA | CIRCLE A EXPRESS INC | | | SCAC3 |
| 14 | CILB | COIL MET | | | SCAC3 |
| 15 | CILB | CENTURY INDUSTRIES LLC | | | SCAC4 |
| 16 | CILC | CIRCLE C FARMS | | | SCAC3 |
| 17 | CILD | CENTRAL ILLIANA MERCHANDISER INC | | | SCAC3 |
| 18 | CILE | CENTRAL ILLINOIS EXPRESS INC | | | SCAC3 |
| 19 | CILE | CASTLETON INDUSTRIES LTD | | | SCAC4 |
| 20 | CILF | CITY OF LAKE FOREST | | | SCAC3 |
| 21 | CILG | CARTWRIGHT LOGISTICS | | | SCAC4 |
| 22 | CILH | CIRCLE L TOWING INC | | | SCAC3 |
| 23 | CILI | CITATION LOGISTICS | | | SCAC4 |
| 24 | CILJ | COASTAL INTERSTATE LOGISTIC LLC | | | SCAC4 |
| 25 | CILK | CAR-DALE TRANSPORTATION LTD | | | SCAC4 |
| 26 | CILL | CONTINENTAL LIMOUSINE LTD | | | SCAC3 |
| 27 | CILM | CIRCLE D LUMBER CO | | | SCAC3 |
| 28 | CILM | CIRCLE D LUMBER CO | | | SCAC4 |
| 29 | CILN | CHRIS-LYNN CARTAGE INC | | | SCAC3 |
| 30 | CILO | CAMILO TRANSPORT | | | SCAC3 |
| 31 | CILO | CARRILLOS TRUCKING | | | SCAC4 |
| 32 | CILP | CARRILLO ENTERPRISES | | | SCAC3 |
| 33 | CILP | CONTINUUM INTERNATIONAL LOGISTICS I | | | SCAC4 |
| 34 | CILQ | CENTRAL ILLINOIS OIL TRANSPORTS INC | | | SCAC3 |
| 35 | CILQ | CHANNEL ISLANDS LOGISTICS INC | | | SCAC4 |
| 36 | CILR | CLASSIC LIMOUSINE SERVICE (A DIVISI | | | SCAC3 |
| 37 | CILS | CENTRAL ILLINOIS TRANSFER & STORAGE | | | SCAC3 |
| 38 | CILT | COLUMBIA INLAND TRUCKING CO | | | SCAC3 |
| 39 | CILT | CORAL ISLE LIMITED | | | SCAC4 |
| 40 | CILU | CARGOSTORE WORLDWIDE TRADING LIMITED | | GB | BIC |
| 41 | CILU | CONTAINER INVESTMENT LEASING ENGINE | | | SCAC3 |
| 42 | CILU | CARGOSTORE INT LTD | | | SCAC4 |
| 43 | CILV | CARTERM INTERMODAL LOGISTICS INC | | | SCAC4 |
| 44 | CILW | CARTIER LIMOUSINE SERVICE | | | SCAC3 |
| 45 | CILW | CARTIER LIMOUSINE SERVICE | | | SCAC4 |
| 46 | CILX | Union Tank Car Co. | added 7/1956; 10/1957; eliminated 1/1958 | | NAKINA |
| 47 | CILX | Canadian Industries (1954) Ltd. | added 10/1954; eliminated 7/1956 | | NAKINA |
| 48 | CILX | Canadian Industries Ltd. | 7/1930-1/1943; 1/1945 (not listed); 1/1946-7/1954; eliminated 10/1954 | | NAKINA |
| 49 | CILX | Union Tank Car Co. | added 7/56; 10/57; eliminated 1/58 | | NRHS |
| 50 | CILX | Canadian Industries Ltd. | 4/38-1/52 | | NRHS |
| 51 | CILX | Canadian Industries (1954) Ltd. | eliminated 7/56 | | NRHS |
| 52 | CILX | UNION TANK CAR CO. (CANADIAN INDUSTRIES LTD.) | | | PWRC |
| 53 | CILY | CAIN, LARRY TRUCKING | | | SCAC3 |
| 54 | CILY | CAPITAL IMPORTER LLC | | | SCAC4 |
| 55 | CILZ | CENTRAL ILLINOIS LIGHT CO. | | | PWRC |
