| 701 | QS | Travel Service, a.s. | ICAO: TVS, Callsign: Skytravel, Designator QS recalled by IATA | CZ | AVCODES |
| 702 | QS | African Safari Airways Ltd. | ICAO: QSC, Callsign: Zebra, Ceased operations. Designator QS recalled by IATA | EAK | AVCODES |
| 703 | QS | Smartwings, a.s. | ICAO: TVS, Callsign: Skytravel, Name changed from Travel Service, a.s. w.e.f. 10 December 2018. Designator QS reinstated by IATA | CZ | AVCODES |
| 704 | QSBA | QUE SABROSA | | | SCAC4 |
| 705 | QSC | African Safari Airways Ltd. | IATA: QS, Callsign: Zebra, Ceased operations. Designator QS recalled by IATA | EAK | AVCODES |
| 706 | QSC | African Safari Airways | IATA: QS | | ICAO1 |
| 707 | QSC | Queens Surface Corp. | City: New York | US-NY | TRAFFIC |
| 708 | QSCP | QUAKER SALES CORP | | | SCAC4 |
| 709 | QSDS | QUICKWAY SPECIAL DELIVERY SERVICE | | | SCAC3 |
| 710 | QSDV | QUICKSILVER DELIVERY INC | | | SCAC3 |
| 711 | QSEC | QUICK SHIP ELECTRONICS | | | SCAC4 |
| 712 | QSEP | QUICKSILVER EXPRESS COURIER OF GEOR | | | SCAC3 |
| 713 | QSGL | QUICK SAND & GRAVEL LLC | | | SCAC4 |
| 714 | QSIN | QUICK SHOT INC | | | SCAC3 |
| 715 | QSLG | QUICK STAR LOGISTICS | | | SCAC4 |
| 716 | QSM | Qeshm Air | IATA: QB, Callsign: Qeshm Air, IATA Prefix: 237, ICAO Designator changed from IRQ. | IR | AVCODES |
| 717 | QSMO | QUALITY SERVICES MOVING | | | SCAC4 |
| 718 | QSMX | Quaker State Corp. | added 10/1987; 1/1994; eliminated 10/1994; 7/2000-7/2005 (not listed) | | NAKINA |
| 719 | QSMX | Quaker State Oil Refining Corp. | 4/1938-1/1980; eliminated 10/1987 | | NAKINA |
| 720 | QSMX | Quaker State Oil Refining Co. | 7/1930-7/1937 | | NAKINA |
| 721 | QSMX | Quaker State Oil Refining Corp. | 4/38-1/80; eliminated 10/87 | | NRHS |
| 722 | QSMX | Quaker State Corp. | added 10/87; 1/94; eliminated 10/94; 7/2000 | | NRHS |
| 723 | QSMX | QUAKER STATE OIL REFINING CORPORATION | | | PWRC |
| 724 | QSMX | Quaker State Oil Refining Corporation | | | RSRV |
| 725 | QSMX | QUAKER STATE OIL REFINING CORP | | | SCAC3 |
| 726 | QSOC | QUALITY STATE OIL CO INC | | | SCAC4 |
| 727 | QSOX | Quaker State Oil Refining Corporation | | | RSRV |
| 728 | QSPS | QUALITY STAR PRODUCTS LTD | | | SCAC4 |
| 729 | QSR | SR Jet Co. Ltd. | Callsign: Sparkle Roll, | RCH | AVCODES |
| 730 | QSR | Bangor and Aroostook Rd. Co. | added 4/2001; 7/2005 | | NAKINA |
| 731 | QSR | Quebec Southern Ry. | added 4/1997; 7/2000; eliminated 4/2001; eliminated 4/2002 | | NAKINA |
| 732 | QSR | Quebec Southern Ry. | added 4/97; 7/2000; eliminated 4/2001 | | NRHS |
| 733 | QSR | Bangor and Aroostook Rd. Co. | added 4/2001 | | NRHS |
| 734 | QSR | BANGOR & AROOSTOCK RR CO. [QUEBEC SOUTHERN RAILWAY] | | | PWRC |
| 735 | QSR | Bangor and Aroostook Railroad (Montreal, Maine & Atlantic) | | | RSRV |
| 736 | QSR | Quebec Southern Railway | | CDN | TRAFFIC |
| 737 | QSRZ | QUALITY SERVICE RAIL CAR REPAIR | | | PWRC |
| 738 | QSST | Q S STORAGE & TRANSFER COMPANY | | | SCAC3 |
| 739 | QSSU | PT. INDONESIA TSINGSHAN STAINLESS STEEL | | RI | BIC |
| 740 | QSTE | QST EXPRESS INC | | | SCAC3 |
| 741 | QSTG | QUEST GLOBAL INC | | | SCAC4 |
| 742 | QSTI | QUEST INDUSTRIES INC | | | SCAC4 |
| 743 | QSTK | QUICK SHOT TRUCKING INC | | | SCAC4 |
| 744 | QSTN | QUALITY SERVICES & TRANSFER INC | | | SCAC4 |
| 745 | QSTS | Q'S TRANSPORT | | | SCAC4 |
| 746 | QSTT | QUEST TRANSPORTATION | | | SCAC3 |
| 747 | QT | Transportes Aereos Mercantiles Panamericanos S.A., (TAMPA) | ICAO: TPA, Callsign: Tampa, IATA Prefix: 729, Name changed to Transportes Aereos Mercantiles Panamericanos S.A., (TAMPA) t/a Avianca Cargo w.e.f. 28 May 2013. | CO | AVCODES |
| 748 | QT | Regional Air PTY Ltd. | | PNG | AVCODES |
| 749 | QT | Inter City Airlines | Ceased operations on 01 August 1983. Name changed from Alidair | GB | AVCODES |
| 750 | QT | Aer Turas Teoranta | ICAO: ATT, Callsign: Quebec Tango, | IRL | AVCODES |
| 751 | QT | Transportes Aereos Mercantiles Panamericanos S.A., (TAMPA) t/a Avianca Cargo | ICAO: TPA, Callsign: Tampa, IATA Prefix: 729, Name changed from Transportes Aereos Mercantiles Panamericanos S.A., (TAMPA) w.e.f. 28 May 2013. | CO | AVCODES |
| 752 | QT | Queens Transit | City: New York | US-NY | TRAFFIC |
| 753 | QTAC | QUEENS TRUCKING AND CONSTRUCTION IN | | | SCAC4 |
| 754 | QTAP | QUALITY TRANSPORTATION INC | | | SCAC3 |
| 755 | QTAP | QUEST TRANSPORT LLC | | | SCAC4 |
| 756 | QTCC | QUALITY CONTRACT CARRIERS INC | | | SCAC3 |
| 757 | QTCI | QUEST TRANSPORTATION COMPANY INC | | | SCAC3 |
| 758 | QTCL | QUICK TURN CARGO LLC | | | SCAC4 |
| 759 | QTCO | QUALITY TRADING CO L L C | | | SCAC4 |
| 760 | QTCR | QUIVICAN TRUCKING CORP | | | SCAC4 |
| 761 | QTCU | QT CONTAINER LINE (HK) LIMITED | | HK | BIC |
| 762 | QTEC | QUALTECH INC | | | SCAC4 |
| 763 | QTEF | QUICK TRIP EXPRESS FREIGHT SERVICE | | | SCAC4 |
| 764 | QTFF | QUINTANA, TONY FREIGHT FORWARDERS I | | | SCAC3 |
| 765 | QTI | Quaboag Transfer | | CDN | TRAFFIC |
| 766 | QTIA | QUALITY TRANSPORT OF IOWA INC | | | SCAC3 |
| 767 | QTIB | QUEEN TRANSPORT INC | | | SCAC4 |
| 768 | QTIC | Q T INC | | | SCAC3 |
| 769 | QTIC | Q T INC | | | SCAC4 |
| 770 | QTIG | QUALITY TRUCKING INC | | | SCAC3 |
| 771 | QTII | Q T I | | | SCAC4 |
| 772 | QTIM | QC TECHNIQUES INC | | | SCAC4 |
| 773 | QTIN | QUALITY TRUCKING INC | | | SCAC3 |
| 774 | QTIN | QUALITY TRUCKING INC | | | SCAC4 |
| 775 | QTIQ | QUORUM TECHNOLOGIES INC | | | SCAC4 |
| 776 | QTJA | QUINTANA TRUJILLO, JOSE ANTONIO | | | SCAC4 |
| 777 | QTJL | QUIROZ TRUJILLO, JOSE LUIS | | | SCAC4 |
| 778 | QTKI | QUALITY TRUCKING INC | | | SCAC4 |
| 779 | QTKL | QUALITY TRUCK LINES INC | | | SCAC3 |
| 780 | QTLD | QUEENSWAY TANK LINES INC | | | SCAC3 |
| 781 | QTLI | QUALITY TRANSPORTATION & LOGISTICS | | | SCAC4 |
| 782 | QTLJ | QUALITY TRANSPORTATION LLC | | | SCAC4 |
| 783 | QTLL | QUALITY TRANS LOGISTICS LLC | | | SCAC4 |
| 784 | QTLT | QUIETT TRANSPORTATION LTD | | | SCAC3 |
| 785 | QTLY | QUEEN TRANSPORTATION LLC | | | SCAC4 |
| 786 | QTMU | QUANTUM FUEL SYSTEM LLC | | USA | BIC |
| 787 | QTNB | QUALITY TRANSPORTATION SERVICES (N | | | SCAC4 |
| 788 | QTNH | QUINTAN HOLDINGS LTD | | | SCAC3 |
| 789 | QTNM | QUALTIY TRACTOR & MACHINERY INC | | | SCAC3 |
| 790 | QTNV | QUALITY TRANSPORTATION SERVICES OF | | | SCAC3 |
| 791 | QTPC | QUINTANA TRANSPORTATION CO | | | SCAC4 |
| 792 | QTPI | Q TRANSPORT INC | | | SCAC4 |
| 793 | QTPL | QUICK TRANSPORT LLC | | | SCAC4 |
| 794 | QTPS | QUALITY TRANSPORTATION SERVICES INC | | | SCAC4 |
| 795 | QTR | Qatar Airways (W.L.L.) | IATA: QR, Callsign: Qatari, IATA Prefix: 157, Name changed to Qatar Airways Group Q.C.S.C. | Q | AVCODES |
| 796 | QTR | Qatar Airways Group Q.C.S.C. | IATA: QR, Callsign: Qatari, IATA Prefix: 157, Name changed from Qatar Airways (W.L.L.) | Q | AVCODES |
| 797 | QTR | Qatar Airways | IATA: QR | | ICAO1 |
| 798 | QTR | Qatar Airways | | Q | TRAFFIC |
| 799 | QTRB | QURAISHI TRUCKING | | | SCAC4 |
| 800 | QTRC | QUEENS TRUCKING | | | SCAC4 |
