| 1 | EO | Congo Airlines | ICAO: ALX, Callsign: All Congo, Name changed to Hewa Bora Airways. Designator EO* reinstated by IATA | ZRE | AVCODES |
| 2 | EO | Express One International, Inc. | ICAO: LHN, Callsign: Longhorn, Found in 1983. Ceased operations. | USA | AVCODES |
| 3 | EO | Alliance Airlines Sprl | ICAO: ALX, Callsign: All Congo, Name changed to Congo Airlines | ZRE | AVCODES |
| 4 | EO | Euroflite | Formed by Cabair and Executive Express for schedules services. | GB | AVCODES |
| 5 | EO | Hewa Bora Airways | ICAO: ALX, Callsign: All Congo, IATA Prefix: 663, Founded in 1994. Ceased operations in 2011. Name changed from Congo Airlines. Designator EO* reinstated by IATA | ZRE | AVCODES |
| 6 | EO | flyCongo | ICAO: ALX, Callsign: Allcongo, IATA Prefix: 663, Founded in 2012. Commenced operations on 24 March 2012. Ceased operations in October 2012 when merged into Compagnie Africaine d'Aviation (CAA). Formerly Hewa Bora Airways | ZRE | AVCODES |
| 7 | EO | Air Go Egypt | ICAO: AGY, Callsign: Egyptian Bird, Designator EO recalled by IATA | ET | AVCODES |
| 8 | EO | Ikar, LLC t/a Pegas Fly | ICAO: KAR, Callsign: Krasjet, IATA Prefix: 770, Founded on 15 June 1993. IATA designator changed from IK*. Name changed from Ikar, LLC. | RUS | AVCODES |
| 9 | EOA | Elilombarda S.R.L. | Callsign: Lombarda, | I | AVCODES |
| 10 | EOA | Elilombarda | | | ICAO1 |
| 11 | EOAN | ESQUIVEL OCHOA, ADRIAN | | | SCAC4 |
| 12 | EOCA | ENSCO OFFSHORE COMPANY | | | SCAC4 |
| 13 | EOCL | EDWARDS OIL COMPANY OF | | | SCAC4 |
| 14 | EOCN | ECHOLS OIL CO INC | | | SCAC4 |
| 15 | EOCO | EDDYVILLE OIL COMPANY | | | SCAC3 |
| 16 | EOCO | ENVIRONMENT CANADA EMISSIONS RESEAR | | | SCAC4 |
| 17 | EOCT | EOC TRANSPORT | | | SCAC4 |
| 18 | EOCW | EASTPORT OCEAN TRADING CORP | | | SCAC4 |
| 19 | EOCX | Ensign Oil Co., Inc. | 8/1920 | | NAKINA |
| 20 | EOCX | ENSIGN OIL CO., INC. | | | PWRC |
| 21 | EOCY | EDISON OIL COMPANY | | | SCAC4 |
| 22 | EODI | EXPAND-O DISTRIBUTION WAREHOUSING S | | | SCAC3 |
| 23 | EODN | EOD LOGISTICS INC | | | SCAC4 |
| 24 | EODU | PENTALVER TRANSPORT LIMITED | | GB | BIC |
| 25 | EOEP | EAGLE ONE EXPRESS | | | SCAC3 |
| 26 | EOEP | EDWARDS GROUP | | | SCAC4 |
| 27 | EOES | EK ONKAR EXPRESS | | | SCAC4 |
| 28 | EOFF | EOFF, LOREN TRUCKING | | | SCAC3 |
| 29 | EOFP | EIGHT ONE FIVE (815) PALLETS INC | | | SCAC4 |
| 30 | EOFT | EIGHT ONE FIVE TWO ZERO THREE (8152 | | | SCAC4 |
| 31 | EOGC | ENCORE LOGISTICS | | | SCAC4 |
| 32 | EOGF | EOG FREIGHT SYSTEM INC | | | SCAC3 |
| 33 | EOGX | Union Carbide Ethylene Oxide/Glycol Co., a Subsidiary of The Dow Chemical Co. U.S.A. | 7/2005 | | NAKINA |
| 34 | EOGX | Union Carbide Ethylene Oxide/Glycol Co. | added 7/1984; 1/1994-7/2000 | | NAKINA |
| 35 | EOGX | Union Carbide Ethylene Oxide/Glycol Co. | added 7/84; 1/94-7/2000 | | NRHS |
| 36 | EOGX | UNION CARBIDE ETHYLENE OXIDE/GLYCOL CO. (DOW CHEMICAL CO. U.S.A.) | | | PWRC |
| 37 | EOGX | Union Carbide Ethylene Oxide/Glycol Co. | | | RSRV |
| 38 | EOGX | UNION CARBIDE ETHYLENE OXIDE/GLYCOL | | | SCAC4 |
| 39 | EOHI | EXPRESS 100 INC | | | SCAC4 |
| 40 | EOHU | ESPINA OBRAS HIDRAULICAS S.A | | E | BIC |
| 41 | EOHU | ESPINA OBRAS HIDRAULICAS SA | | | SCAC4 |
| 42 | EOIC | EAGLE OIL CO INC | | | SCAC4 |
| 43 | EOIL | EDEN OIL CO INC | | | SCAC4 |
| 44 | EOIN | EAGLE OIL INC | | | SCAC4 |
| 45 | EOK | Aero K Airlines | IATA: RF, Callsign: Aerokorea, AOC acquired on 28 December 2020. Commenced operations on 14 April 2021. Name changed from KAIR Airlines. | PRK | AVCODES |
| 46 | EOK | Aero K | | ROK | TRAFFIC |
| 47 | EOL | Airailes | Callsign: Eole, | F | AVCODES |
| 48 | EOL | Airailes | | | ICAO1 |
| 49 | EOLC | EMERSON OIL CO INC | | | SCAC4 |
| 50 | EOLI | EASY ON LOGISTICS INC | | | SCAC4 |
| 51 | EOLL | ELITE OIL LLC | | | SCAC4 |
| 52 | EOLO | EOLO FINANCIERA S A (PANAMA) | | | SCAC4 |
| 53 | EOLS | EOLOS SHIPMANAGEMENT S A | | | SCAC4 |
| 54 | EOLU | EXIM CONTAINER SERVICES PTE. LTD. | | SGP | BIC |
| 55 | EOLU | EXIM CONTAINER SERVICES PRIVATE LTD | | | SCAC3 |
| 56 | EOLU | EXIM CONTAINER SERVICES PTE LTD | | | SCAC4 |
| 57 | EOLX | EOL LEASING LLC | | | SCAC4 |
| 58 | EOM | Aero Ermes, S.A. de C.V. | Callsign: Aero Ermes, | MEX | AVCODES |
| 59 | EOM | Aero Ermes | | | ICAO1 |
| 60 | EOMO | EASTOMO COMPANY S A | | | SCAC3 |
| 61 | EON | e-on Kraftwerke GmbH | | D | TRAFFIC |
| 62 | EONE | EXPRESS ONE INC | | | SCAC4 |
| 63 | EONO | ECONO CAR OF JACKSONVILLE | | | SCAC3 |
| 64 | EOOI | ENVIRITE OF OHIO INC | | | SCAC4 |
| 65 | EOP | Execujet Flight Operations (PTY) Ltd. | Callsign: Execujet Ops, | ZA | AVCODES |
| 66 | EOP | Eolo Plus, S.A. de C.V. | Callsign: Eolo Plus, | MEX | AVCODES |
| 67 | EOPX | Eastland Oil & Refining Co. | 8/1920 | | NAKINA |
| 68 | EOPX | EASTLAND OIL & REFINING CO. | | | PWRC |
| 69 | EORS | EASTERN OREGON RENTAL & SALES | | | SCAC4 |
| 70 | EORU | ECORAIL INC | | | SCAC3 |
| 71 | EORU | EURORA S R L | | | SCAC4 |
| 72 | EORX | Cities Service Co. | added 4/1978; eliminated 7/1978 | | NAKINA |
| 73 | EORX | Cities Service Pipe Line Co. | added 10/1967; 4/1970-1/1975; eliminated 4/1978 | | NAKINA |
| 74 | EORX | Cities Service Oil Co. | added 4/1963; 7/1965-10/1966; eliminated 10/1967 | | NAKINA |
| 75 | EORX | Cities Service Petroleum Co. | added 7/1962; eliminated 4/1963 | | NAKINA |
| 76 | EORX | Cities Service Oil Co. | 1/1950-4/1961; eliminated 7/1962 | | NAKINA |
| 77 | EORX | Cities Service Oil Co. of Delaware | 4/1938-4/1947 | | NAKINA |
| 78 | EORX | Empire Oil & Refining Co. | 7/1937 | | NAKINA |
| 79 | EORX | Cities Service Oil Co. of Delaware | Apr-38 | | NRHS |
| 80 | EORX | Cities Service Oil Co. | 1/52-10/66; eliminated 10/67 | | NRHS |
| 81 | EORX | Cities Service Pipe Line Co. | added 10/67; 4/70-1/75; eliminated 4/78 | | NRHS |
| 82 | EORX | Cities Service Co. | added 4/78; eliminated 7/78 | | NRHS |
| 83 | EORX | (CSOX) RETIRED 09-09-92 ATP (1190) [CITIES SERVICE OIL CO.] | | | PWRC |
| 84 | EORX | Cities Service Oil Co. | | USA | TRAFFIC |
| 85 | EOS | Eliossola Srl | Callsign: Eliossola, | I | AVCODES |
| 86 | EOS | Eliossola | | | ICAO1 |
| 87 | EOS | Swallow Coach Company (EOS) | | GB | TRAFFIC |
| 88 | EOSN | ECHO OILFIELD SERVICES INC | | | SCAC4 |
| 89 | EOSP | ELECTRO OPTICAS SUPERIOR S A DE C | | | SCAC4 |
| 90 | EOSR | EXPRESS OCEAN SERVICES | | | SCAC4 |
| 91 | EOSS | EAST OASIS INC | | | SCAC3 |
| 92 | EOSU | SHELL CATALYSTS & TECHNOLOGIES PTE LTD | | SGP | BIC |
| 93 | EOSU | CR/CRITERION MARKETING ASIA PACIFIC | | | SCAC4 |
| 94 | EOTB | EAST OF THE BAY LLC | | | SCAC4 |
| 95 | EOTI | ELITE OIL TRANSPORT INC | | | SCAC4 |
| 96 | EOTL | EASY ON TAIL LIGHTS | | | SCAC4 |
| 97 | EOTR | ECONOMY TRANSPORT CORP | | | SCAC3 |
| 98 | EOTU | EUROPE ONLINE TRADE PLC. | | BG | BIC |
| 99 | EOWX | Empire Oil Works, Inc. | 7/1930 | | NAKINA |
| 100 | EOWX | Empire Oil Works, Inc. (Wolverine-Empire Refining Co.) | 7/1932 | | NAKINA |
