| 1 | QD | Air Class Lineas Aereas (Aerovip Ltda) | ICAO: QCL, Callsign: Acla, Founded in 1996. Commenced operations in 1997. | ROU | AVCODES |
| 2 | QD | Air Atlantic | | E | AVCODES |
| 3 | QD | Qwestair | ICAO: QWA, Designator QD* recalled by IATA | AUS | AVCODES |
| 4 | QD | Sadia Transportes Aereos S.A. | Callsign: Sadia, | BR | AVCODES |
| 5 | QD | Transportes Aéreas Salvador | | BR | AVCODES |
| 6 | QD | Air Limousin T.A. | ICAO: LIM, ICAO designator changed to LMT | F | AVCODES |
| 7 | QD | Air Limousin T.A. | ICAO: LMT, ICAO designator changed from LIM | F | AVCODES |
| 8 | QD | Air Limousin T.A. | ICAO: LMT, Callsign: Air Limousin, | F | AVCODES |
| 9 | QD | LLC "Dobrolet" | ICAO: DBR, Callsign: Dobrolet, Ceased opeations on 04 August 2014. Founded in October 2013. Low cost subsidiary of Aeroflot. | RUS | AVCODES |
| 10 | QD | JC (Cambodia) International Airlines | ICAO: JCC, Callsign: Cambo, Planned startup subject to licence approval in April 2017. | K | AVCODES |
| 11 | QDA | Qingdao Airlines Co., Ltd. | IATA: QW, Callsign: Sky Legend, IATA Prefix: 912, | PRC | AVCODES |
| 12 | QDBI | QUINN DISTRIBUTORS INC | | | SCAC3 |
| 13 | QDBI | QUINN DISTRIBUTORS INC | | | SCAC4 |
| 14 | QDCC | Q. D. CARTAGE COMPANY | | | SCAC3 |
| 15 | QDCE | QUAD CITY EXPRESS INC | | | SCAC4 |
| 16 | QDCI | QUICK DELIVERY COMPANY OF INDIANA I | | | SCAC3 |
| 17 | QDFS | QUADTRANS FREIGHT SYSTEMS INC | | | SCAC3 |
| 18 | QDHI | Q & D | | | SCAC4 |
| 19 | QDIC | QUESTRADE INC | | | SCAC4 |
| 20 | QDIN | QUICK DELIVERY INC | | | SCAC4 |
| 21 | QDLB | QUADREL BROS TRUCKING CO INC | | | SCAC3 |
| 22 | QDLC | QUICK DELIVERY LLC | | | SCAC4 |
| 23 | QDR | Quadrotur Aero | | KZ | AVCODES |
| 24 | QDSA | QS DELIVERY SERVICE INC | | | SCAC4 |
| 25 | QDSI | QUICK DELIVERY SERVICE | | | SCAC3 |
| 26 | QDSI | QUICK DELIVERY SERVICE INCORPORATED | | | SCAC4 |
| 27 | QDSO | Q D S TRANSPORTATION | | | SCAC4 |
| 28 | QDST | Q.D.S. TRANSPORTATION CO | | | SCAC3 |
| 29 | QDSV | QUALITY DISTRIBUTION SERVICES INC | | | SCAC3 |
| 30 | QDTP | QUADCO EQUIPMENT INC | | | SCAC4 |
| 31 | QDTS | QUADRANT TRANSPORTATION SYSTEMS | | | SCAC4 |
