| 1 | UG | Tuninter, S.A. | ICAO: TUI, IATA Prefix: 150, Name changed to Sevenair w.e.f. 07 July 2007. ICAO code SEN | TN | AVCODES |
| 2 | UG | Empresa (Aero Uruguay), S.A. | ICAO: AUO, Callsign: Uniform Oscar, Founded in 1977. Ceased operations in 2005. Designator recalled by IATA | ROU | AVCODES |
| 3 | UG | Uganda Aviation Services | Callsign: Ugandair, | EAU | AVCODES |
| 4 | UG | Sevenair | ICAO: SEN, Callsign: Sevair, IATA Prefix: 150, Name changed to Tunisair Express w.e.f. 14 January 2011. Name changed from Tuninter, S.A. w.e.f. 07 July 2007. | TN | AVCODES |
| 5 | UG | Tunisair Express | ICAO: TUX, Callsign: Tunexpress, IATA Prefix: 150, Name changed from Sevenair w.e.f. 14 January 2011 and previously from Tuninter, S.A. w.e.f. 07 July 2007. | TN | AVCODES |
| 6 | UGA | Uganda Airlines Corp. | IATA: QU, Callsign: Uganda, | EAU | AVCODES |
| 7 | UGA | Uganda Airlines Holdings Ltd. | IATA: QU, Callsign: Uganda, Name changed from Uganda Airlines Corp. Operations restarted. Ceased operations in October 2000 | EAU | AVCODES |
| 8 | UGA | Uganda Airlines Corp. | IATA: QU, Callsign: Uganda, Name changed to Uganda Airlines Holdings Ltd. Operations restarted. Ceased operations in October 2000 | EAU | AVCODES |
| 9 | UGA | Meridiana African Airlines (U) Limited d/b/a Air Uganda | IATA: U7, Callsign: Ugdana, IATA Prefix: 926, Founded in 2007. | EAU | AVCODES |
| 10 | UGA | Uganda Airlines | | | ICAO1 |
| 11 | UGAB | UNIVERSAL GEMS AND BEADS | | | SCAC4 |
| 12 | UGB | Meridiana Africa Airlines (U) Ltd | Callsign: Ugawings, | EAU | AVCODES |
| 13 | UGBL | UNIPACK GLOBAL RELOCATION INC | | | SCAC4 |
| 14 | UGC | Urgemer Canarias, S.L. | Callsign: Urgemer, | E | AVCODES |
| 15 | UGC | Urgemer Canarias | | | ICAO1 |
| 16 | UGCU | UNIPER GLOBAL COMMODITIES SE | | D | BIC |
| 17 | UGD | Uganda National Airlines Company Limited d/b/a/ Uganda Airlines | IATA: UR, Callsign: Crested, | EAU | AVCODES |
| 18 | UGEI | UNITED GROUP EXPRESS INC | | | SCAC4 |
| 19 | UGEZ | UNITED GRAIN ELEVATOR 2 | | | PWRC |
| 20 | UGFS | UNGER FREIGHT SERVICES INC | | | SCAC4 |
| 21 | UGII | UNITED GROUP INTERNATIONAL INC | | | SCAC4 |
| 22 | UGJ | UG Jet, s.r.o. | Callsign: Unijet, | CZ | AVCODES |
| 23 | UGJ | Uppsala - Gävle Järnväg | 1874 - 1933 | S | svenska-lok.se |
| 24 | UGL | Inter-Island Air, Inc. | Callsign: Ugly Van, | USA | AVCODES |
| 25 | UGL | Inter-Island Air | | | ICAO1 |
| 26 | UGLC | UNI GLOBAL LOGISTICS | | | SCAC4 |
| 27 | UGLF | USA GRANITE INC | | | SCAC4 |
| 28 | UGLI | UNION TRANSFER & STORAGE INC | | | SCAC4 |
| 29 | UGLK | USS GREAT LAKES LLC | | | SCAC4 |
| 30 | UGLL | UNITED GLOBAL LOGISTICS INC | | | SCAC4 |
| 31 | UGLP | UNICARGO GLOBAL LOGISTICS PRIVATE L | | | SCAC4 |
| 32 | UGLS | USA GLOBAL LOGISTICS LLC | | | SCAC4 |
| 33 | UGLT | UNITED GLOBAL TRANSPORT INC | | | SCAC4 |
| 34 | UGLU | UNIGLOBAL SHIPPING COMPANY LIMITED | | HK | BIC |
| 35 | UGLW | UNITED GROUP LOGISTICS UGL | | | SCAC4 |
| 36 | UGMA | U GET MOORE EXPRESS INC | | | SCAC4 |
| 37 | UGMT | U G M TRANSPORT INC | | | SCAC4 |
| 38 | UGMU | GREENCOMPASS MARINE S.A. | | PA | BIC |
| 39 | UGMU | EVERGREEN INTERNATIONAL (USA) CORPORATION | | | PWRC |
| 40 | UGMU | Evergreen International (Greencompass Marine) | | | RSRV |
| 41 | UGMU | UNIGLORY MARINE CORP | | | SCAC4 |
| 42 | UGN | Yuzhnaya Aircompany | Callsign: Pluton, | KZ | AVCODES |
| 43 | UGN | Yuzhnaya Aircompany | | | ICAO1 |
| 44 | UGNC | UGLEM NESS CO INC | | | SCAC4 |
| 45 | UGNY | UNITED GLOBAL SERVICES (NY) CORP | | | SCAC4 |
| 46 | UGP | Shar Ink Ltd. | Callsign: Sharnik, | RUS | AVCODES |
| 47 | UGP | Shar Ink | | | ICAO1 |
| 48 | UGPU | ROZA MIRA LLC | | RUS | BIC |
| 49 | UGPX | United Gas Pipe Line Co. | 4/1938-1/1943 | | NAKINA |
| 50 | UGPX | United Gas Pipe Line Co. | Apr-38 | | NRHS |
| 51 | UGPX | UNITED GAS PIPE LINE CO. | | | PWRC |
| 52 | UGRD | UNION GANADERA REGIONAL DE COAHUILA | | | SCAC4 |
| 53 | UGS | SKA Air and Logistics (Uganda) Limited | Callsign: Sky Uganda, | EAU | AVCODES |
| 54 | UGSU | UCAK SHIPPING CORP | | PA | BIC |
| 55 | UGSX | United Gas Public Service Co. | 7/1932-7/1937 | | NAKINA |
| 56 | UGSX | UNITED GAS PUBLIC SERVICE CO. | | | PWRC |
| 57 | UGTI | UNGER TRANSPORT INC | | | SCAC4 |
| 58 | UGTU | BOECKMANS N V | | | SCAC4 |
| 59 | UGX | East Afrian Airlines Limited | IATA: QU, Callsign: Crane, IATA designator changed from QU* | EAU | AVCODES |
| 60 | UGX | East Afrian Airlines Limited | IATA: QU, Callsign: Crane, IATA designator changed to QU | EAU | AVCODES |
| 61 | UGX | East Afrian Airlines Limited | Callsign: Crane, Designator QU* recalled by IATA. | EAU | AVCODES |
| 62 | UGX | East African | IATA: QU | | ICAO1 |
