| 701 | OD | Malindo Airways Sdn Bhd (Malindo Air) | ICAO: MXD, Callsign: Malindo Express, ICAO callsign changed to Malindo. | MAL | AVCODES |
| 702 | OD | Malindo Airways Sdn Bhd (Malindo Air) | ICAO: MXD, Callsign: Malindo, Name changed to Malindo Airways Sdn Bhd d/b/a Batik Air. ICAO callsign changed from Malindo Express. | MAL | AVCODES |
| 703 | OD | Malindo Airways Sdn Bhd d/b/a Batik Air | ICAO: MXD, Callsign: Malindo, Name chanegd from Malindo Airways Sdn Bhd (Malindo Air). ICAO callsign changed from Malindo Express. | MAL | AVCODES |
| 704 | OD | Oftobanen Drift AS | | NO | VKM |
| 705 | OD&W | Oneida & Western R.R. | 4/1938-7/1954 | | NAKINA |
| 706 | OD&W | Oneida & Western R.R. | 4/38-1/52 | | NRHS |
| 707 | OD&W | ONIEDA & WESTERN RAILROAD | | | PWRC |
| 708 | ODA | Aircompany Black Sea Airlines LLC | | UA | AVCODES |
| 709 | ODAI | ODOM ANTENNAS INC | | | SCAC3 |
| 710 | ODAK | Odakyu | | J | TRAFFIC |
| 711 | ODAKB | Odakyu Bus | | J | TRAFFIC |
| 712 | ODAKHH | Odakyu Hakone Highway Bus Co. | | J | TRAFFIC |
| 713 | ODAQ | ONE A TRUCKING INC (1-A TRUCKING IN | | | SCAC3 |
| 714 | ODB | Air Service | Callsign: Servair, | RMM | AVCODES |
| 715 | ODBS | OLSON DISTRIBUTION SYSTEMS INC | | | SCAC3 |
| 716 | ODBZ | OLD BEN #24 MINE | | | PWRC |
| 717 | ODCN | OVERHEAD DOOR CORPORATION | | | SCAC4 |
| 718 | ODCO | OVERDRIVE CORPORATION | | | SCAC3 |
| 719 | ODCP | OLIVA DELIVERY CORP | | | SCAC4 |
| 720 | ODCS | OLDCASTLE GLASS BURNABY | | | SCAC4 |
| 721 | ODCX | Old Dominion Chapter, National Railway Historial Society | 7/2005 (not listed) | | NAKINA |
| 722 | ODCX | OLD DOMINION CHAPTER, NATIONAL RAILWAY HISTORICAL SOCIETY | | | PWRC |
| 723 | ODCX | OLD DOMINION CHAPTER, NATIONAL RAIL | | | SCAC4 |
| 724 | ODDC | OWENS DELUXE DOLLHOUSE COMPANY | | | SCAC4 |
| 725 | ODDS | ONE DAY DELIVERY SERVICE | | | SCAC3 |
| 726 | ODDT | OLDLAND TRANSPORTATION INC | | | SCAC3 |
| 727 | ODDU | WELFIT ODDY (PTY) LIMITED | | ZA | BIC |
| 728 | ODDU | WELFIT ODDY (PTY) LIMITED | | | SCAC4 |
| 729 | ODDY | ODDYS, A INC | | | SCAC3 |
| 730 | ODEC | ODESSA & CO | | | SCAC4 |
| 731 | ODEG | Ostdeutsche Eisenbahn GmbH | Parchim | D | privat-bahn.de |
| 732 | ODEG | Ostdeutsche Eisenbahn GmbH | | D | TRAFFIC |
| 733 | ODEG | Ostdeutsche Eisenbahngesellschaft | | DE | VKM |
| 734 | ODEI | ODOM ENTERPRISES INC | | | SCAC3 |
| 735 | ODEL | ODELL MOP COMPANY INC | | | SCAC3 |
| 736 | ODEP | ODONNELLS EXPRESS LTD | | | SCAC3 |
| 737 | ODER | OUTSTATE DELIVERY | | | SCAC4 |
| 738 | ODES | ODESSEY CORP | | | SCAC3 |
| 739 | ODES | OPTRON DE MEXICO SA DE CV | | | SCAC4 |
| 740 | ODES | | City: Odessa | UA | TRAFFIC |
| 741 | ODET | KP Odesmiskelektrotrans | City: Odessa | A | TRAFFIC |
| 742 | ODEW | ODEON EVENING WEAR | | | SCAC4 |
| 743 | ODEY | ODEY TRANSPORTATION | | | SCAC3 |
| 744 | ODEY | ODEY TRANSPORTATION | | | SCAC4 |
| 745 | ODF | Osnabrücker Dampflokfreunde e.V. | Osnabrück | D | privat-bahn.de |
| 746 | ODF | Osnabrücker Dampflokfreunde e.V | | DE | VKM |
| 747 | ODFE | OLD DOMINION FREIGHT LINE INC (EXPE | | | SCAC4 |
| 748 | ODFL | OLD DOMINION FREIGHT LINE, INC | | | SCAC3 |
| 749 | ODFL | OLD DOMINION FREIGHT LINE | | | SCAC4 |
| 750 | ODFN | OLD DOMINION FREIGHT LINE INC | | | SCAC4 |
| 751 | ODFS | ODONNELL FREIGHT SYSTEMS | | | SCAC3 |
| 752 | ODFS | ORR, DAVID F TRUCKING LLC | | | SCAC4 |
| 753 | ODGH | ODONOGHUE, JAMES | | | SCAC4 |
| 754 | ODHM | OLDHAM BROS INC | | | SCAC4 |
| 755 | ODHQ | OVERMYER, D H WHSE | | | SCAC3 |
| 756 | ODHT | OLDHAM TRUCKING | | | SCAC3 |
| 757 | ODI | Jonsson, H. Air Taxi | Callsign: Odinn, | IS | AVCODES |
| 758 | ODI | Jonsson, H Air Taxi | | | ICAO1 |
| 759 | ODIC | ON DEMAND INC | | | SCAC4 |
| 760 | ODIM | ODIM SPECTRUM LTD | | | SCAC4 |
| 761 | ODIN | ODIN Logistics AG | | DE | VKM |
| 762 | ODIQ | ODIN INC | | | SCAC3 |
| 763 | ODIR | ORROCK DIRECT INDUSTRIAL COURIER | | | SCAC4 |
| 764 | ODKG | O'DANIEL TRUCKING COMPANY | | | SCAC3 |
| 765 | ODKL | ORCHID TRUCKING LLC | | | SCAC4 |
| 766 | ODLA | OCEAN DRIVE LIMOUSINES INC | | | SCAC4 |
| 767 | ODLC | ODLE CONSTRUCTION CO | | | SCAC3 |
| 768 | ODLC | OMAHA DIRECT LOGISTICS | | | SCAC4 |
| 769 | ODLD | ODYSSEY OVERLAND LLC | | | SCAC4 |
| 770 | ODLG | ODELL TRANSFER AND STORAGE | | | SCAC3 |
| 771 | ODLI | ODONNELL LIMOUSINE INC | | | SCAC3 |
| 772 | ODLL | ODONNELL LTD | | | SCAC3 |
| 773 | ODLL | OIL DEPOT LLC | | | SCAC4 |
| 774 | ODLN | ON DEMAND LOGISTICS INC | | | SCAC4 |
| 775 | ODLO | ODELL OIL CO INC | | | SCAC4 |
| 776 | ODLQ | OAKLEY DEDICATED LOGISTICS LLC | | | SCAC4 |
| 777 | ODLS | OLYMPIC DELIVERY SERVICE INC | | | SCAC3 |
| 778 | ODLY | ODALYS TRUCKING | | | SCAC3 |
| 779 | ODM | Pan African Airways Ltd | IATA: 5F, Callsign: Jetafrica, | EAK | AVCODES |
| 780 | ODM | Pan African Airways | | | ICAO1 |
| 781 | ODMC | ODOM CORPORATION, THE | | | SCAC4 |
| 782 | ODMI | ORTIZ, D & M TRANSPORT INC | | | SCAC4 |
| 783 | ODMK | ODOM TRUCKING | | | SCAC4 |
| 784 | ODMM | ODELL-MCKENZIE MOVING & STORAGE | | | SCAC3 |
| 785 | ODMR | ODOM, W RAY | | | SCAC3 |
| 786 | ODMT | ODOM TRUCKING INC | | | SCAC3 |
| 787 | ODMT | OSADCHUK, M TRUCKING | | | SCAC4 |
| 788 | ODNE | ODEN ENTERPRISES INC | | | SCAC3 |
| 789 | ODNF | OLD NEIGHBORHOOD FOODS | | | SCAC4 |
| 790 | ODNL | ODONNELL, ARTHUR L | | | SCAC3 |
| 791 | ODOJ | ODO, J D & SON TRUCKING | | | SCAC3 |
| 792 | ODON | O'DONNELL, VONDA | | | SCAC4 |
| 793 | ODOR | ODOR TECH | | | SCAC4 |
| 794 | ODOS | OSTRAVSKA DOPRAVNI SPOLEČNOST, a.s. | | CZ | VKM |
| 795 | ODOT | OKLAHOMA DEPARTMENT OF TRANSPORTATION | | | PWRC |
| 796 | ODOX | Old Dominion Oil Co. | 8/1920 | | NAKINA |
| 797 | ODOX | OLD DOMINION OIL CO. | | | PWRC |
| 798 | ODPI | O D P | | | SCAC4 |
| 799 | ODR | Quadrotour Aero, Aircompany | Callsign: Quadro, | KZ | AVCODES |
| 800 | ODRI | OIL-DRI TRANSPORTATION CO | | | SCAC3 |
