| 1 | QR | Qatar Airways (W.L.L.) | ICAO: QTR, Callsign: Qatari, IATA Prefix: 157, Name changed to Qatar Airways Group Q.C.S.C. | Q | AVCODES |
| 2 | QR | Air Satellite, Inc. | ICAO: ASJ, Callsign: Satellite, Designator HV recalled by IATA | CDN | AVCODES |
| 3 | QR | Centrafrique | | RCA | AVCODES |
| 4 | QR | Qatar Airways Group Q.C.S.C. | ICAO: QTR, Callsign: Qatari, IATA Prefix: 157, Name changed from Qatar Airways (W.L.L.) | Q | AVCODES |
| 5 | QR | Queensland Rail | | AUS | TRAFFIC |
| 6 | QRAC | QUARRY RIDGE ASPHALT | | | SCAC4 |
| 7 | QRBQ | QUIRK BROS MOTOR SERVICE | | | SCAC3 |
| 8 | QRBQ | QKR LLC | | | SCAC4 |
| 9 | QRC | Quebec Ry. Corp. Inc. | 7/2000-7/2005 | | NAKINA |
| 10 | QRC | Quebec Ry. Corp. Inc. | Jul-00 | | NRHS |
| 11 | QRC | QUEBEC RAILWAY CORP. | | | PWRC |
| 12 | QRC | Quebec Railway Corporation | | | RSRV |
| 13 | QRC | QUEBEC RAILWAY CORPORATION INC | | | SCAC4 |
| 14 | QREX | General American Transportation Corp. | 7/1937 | | NAKINA |
| 15 | QREX | Quaker City Refrigerator Line (General American Tank Car Corp.) | 7/1935 | | NAKINA |
| 16 | QREX | Quaker City Refrigerator Line | 7/1930-7/1932 | | NAKINA |
| 17 | QREX | QUAKER CITY REFRIGERATOR LINE (GENERAL AMERICAN TRANSPORTATION CORP.) | | | PWRC |
| 18 | QRKQ | QUIRK MOVING & STORAGE | | | SCAC3 |
| 19 | QRKQ | QUARTERBACK TRANSPORTATION INC | | | SCAC4 |
| 20 | QRKT | QUARTERBACK TRANSPORTATION USA INC | | | SCAC4 |
| 21 | QRLS | QUARLES PETROLEUM INC | | | SCAC4 |
| 22 | QRMA | QUIROGA RODRIGUEZ, MARIO ALBERTO | | | SCAC4 |
| 23 | QRMC | QUALITY READY MIX CONCRETE CO | | | SCAC3 |
| 24 | QRMT | Q R M TRANSPORTATION INC | | | SCAC3 |
| 25 | QRN | QR National | Formerly Queensland Rail and Interail | AUS | TRAFFIC |
| 26 | QROG | QIROGA TRANSPORT LLC | | | SCAC4 |
| 27 | QRON | QUINLAN, RON | | | SCAC4 |
| 28 | QRPI | QUALITY REPAIR INC | | | SCAC4 |
| 29 | QRR | Quincy R.R. Co. | 1/1975-7/2005 | | NAKINA |
| 30 | QRR | Quincy R.R. Co. | 1/75-7/2000 | | NRHS |
| 31 | QRR | QUINCY RAILROAD COMPANY | | | PWRC |
| 32 | QRR | Quincy Railroad | | | RSRV |
| 33 | QRRU | Q1 INTERMODAL | | | SCAC3 |
| 34 | QRRU | Q ONE (1) INTERMODAL | | | SCAC4 |
| 35 | QRSM | QRS | | | SCAC4 |
| 36 | QRSX | Quality Railway Services & Supply Co. | 7/2000; eliminated 7/2001; added 10/2001; 7/2005; eliminated 4/2007 | | NAKINA |
| 37 | QRSX | Quality Railway Services & Supply Co. | 7/2000; eliminated 7/2001 | | NRHS |
| 38 | QRSX | QUALITY RAILWAY SERVICES & SUPPLY COMPANY | | | PWRC |
| 39 | QRSX | Quality Railway Services and Supply | | | RSRV |
| 40 | QRSX | QUALITY RAILWAY SERVICES & SUPPLY C | | | SCAC4 |
| 41 | QRT | 4D Air Co. Ltd. | Callsign: Quartet, | T | AVCODES |
| 42 | QRT | 4D Air | | | ICAO1 |
| 43 | QRTC | QUICK RESPONSE TRUCKING CO | | | SCAC3 |
| 44 | QRTC | QUIROGA TRANSFER LLC | | | SCAC4 |
| 45 | QRTT | QUASAR TRANSPORT | | | SCAC3 |
| 46 | QRWS | QUICK ROADWAY SERVICES | | | SCAC4 |
