| 1 | MKO | Markoss Aviation Ltd. | Callsign: Goshawk, | GB | AVCODES |
| 2 | MKO | Markoss Aviation | | | ICAO1 |
| 3 | MKO | Museumseisenbahn Küstenbahn Ostfriesland e.V. | Norden | D | privat-bahn.de |
| 4 | MKOA | MAKO LINES INC | | | SCAC4 |
| 5 | MKOC | MACLASKE | | | SCAC4 |
| 6 | MKOD | MANKO DELIVERY SYSTEMS INC | | | SCAC4 |
| 7 | MKOE | MARKO EXPRESS | | | SCAC4 |
| 8 | MKOF | MEIKO FREIGHT SERVICE, INC | | | SCAC1 |
| 9 | MKOI | MCKINLEY OIL LLC | | | SCAC4 |
| 10 | MKON | Miejski Zakład Komunikacji w Koninie sp. z o.o. | | PL | TRAFFIC |
| 11 | MKontJ | Malmö - Kontinentens Järnväg | 1897 - 1909 | S | svenska-lok.se |
| 12 | MKOR | MARKO TRANSPORTATION | | | SCAC4 |
| 13 | MKOT | MEIKO TRANS CO LTD | | | SCAC4 |
| 14 | MKOU | METIN AKDURAK LTD | | | SCAC4 |
