| 1 | J | Japan | | J | TRAFFIC |
| 2 | J&P | (The) Joplin-Pittsburg R.R. (Co.) | 7/1930-4/1938 | | NAKINA |
| 3 | J&P | The Joplin-Pittsburg Ry. Co. | 7/1923 | | NAKINA |
| 4 | J&P | Joplin-Pittsburg R.R. | Apr-38 | | NRHS |
| 5 | J&P | JOPLIN-PITTSBURG RWY. CO. | | | PWRC |
| 6 | J&SC | Johnstown & Stony Creek R.R. (Co.) | 7/1923-4/1938 | | NAKINA |
| 7 | J&SC | Johnstown & Stony Creek R.R. | Apr-38 | | NRHS |
| 8 | J&SC | JOHNSTOWN & STONET CREEK RAILROAD | | | PWRC |
| 9 | J0 | Jet Link Express Ltd. | ICAO: JLX, IATA Prefix: 402, Founded in 2006. Ceased operations in 2012. | EAK | AVCODES |
| 10 | J0 | Buffalo Airways Ltd. | ICAO: BFL, Callsign: Buffalo, IATA Prefix: 916, Designator J4* recalled by IATA | CDN | AVCODES |
| 11 | J0 | Rutair Limited d/b/a Jam Air Link Express Limited | ICAO: LJM, Callsign: Cool Runnings, | JA | AVCODES |
| 12 | J1 | BusinessJet Class | Computer Reservations Systems (CRS) | USA | AVCODES |
| 13 | J1 | Primair, Inc. | Name changed to One Jet, Inc. Flights operated by Pentastar Aviation Charter, Inc. | USA | AVCODES |
| 14 | J1 | Sun America, Inc. d/b/a JetAmerica | ICAO: BSK, Callsign: Biscayne, | USA | AVCODES |
| 15 | J1 | One Jet, Inc. | Ceased operations on 29 August 2018. Name changed from Primair, Inc. Flights operated by Corporate Flight Management. | USA | AVCODES |
| 16 | J2 | Azerbaijan Hava Yollary | ICAO: AHY, Callsign: Azal, IATA Prefix: 771, Name changed to Azerbaijan Airlines CJSC. | AZ | AVCODES |
| 17 | J2 | Azerbaijan Airlines CJSC | ICAO: AHY, Callsign: Azal, IATA Prefix: 771, Name changed from Azerbaijan Hava Yollary. | AZ | AVCODES |
| 18 | J3 | Northwestern Air Lease Ltd. | ICAO: PLR, Callsign: Polaris, IATA Desigantor changed form CT* | CDN | AVCODES |
| 19 | J4 | Buffalo Airways Ltd. | ICAO: BFL, Callsign: Buffalo, Designator J4* recalled by IATA | CDN | AVCODES |
| 20 | J4 | Air Jamaica Express Limited | ICAO: JMX, Commenced operations on 18 April 1996. IATA Designator changed to JQ. | JA | AVCODES |
| 21 | J4 | Jordan International Air Cargo Company (JIAC) | ICAO: JCI, IATA Prefix: 660, | JOR | AVCODES |
| 22 | J4 | Jet Time A/S | ICAO: JTG, Callsign: Jettime, Commenced operations on 19 September 2006. Filed for bankruptcy on 21 July 2020. | DK | AVCODES |
| 23 | J4 | Badr Airlines | ICAO: BDR, Callsign: Badr Air, IATA Prefix: 367, | SUD | AVCODES |
| 24 | J5 | Alaska Seaplane Service, L.L.C. | Name changed to Kalinin Aviation, L.L.C. d/b/a Alaska Seaplanes. IATA Designator changed from UI* | USA | AVCODES |
| 25 | J5 | Shenzhen Donghai Airlines Co., Ltd. | ICAO: EPA, Callsign: Donghai Air, IATA Prefix: 844, Designator J5* recalled by IATA | PRC | AVCODES |
| 26 | J5 | DAC Aviation (EC) Ltd. | IATA Designator changed to JX | EAK | AVCODES |
| 27 | J5 | Kalinin Aviation, L.L.C. d/b/a Alaska Seaplanes | Name changed from Alaska Seaplane Service, L.L.C. IATA Designator changed from UI* | USA | AVCODES |
| 28 | J6 | Larry's Flying Service, Inc. | | USA | AVCODES |
| 29 | J6 | Jet Ops | ICAO: OPS, Callsign: Ops-Jet, Designator J6* recalled by IATA | UAE | AVCODES |
| 30 | J6 | Cruiser Linhas Aéreas Ltda | ICAO: VCR, Callsign: Voe Cruiser, Commenced operations on 2001. Ceased operations during 2010. | BR | AVCODES |
| 31 | J6 | Airways International Limited | Ceased operations. | JA | AVCODES |
| 32 | J7 | Centre-Avia Airlines, JSC | ICAO: CVC, Callsign: Aviacentre, Founded in 2000. Ceased operations in 2010. | RUS | AVCODES |
| 33 | J7 | ValuJet Airlines, Inc. | ICAO: VJA, Callsign: Critter, Merged in AirTran (FL). Founded in 1992. Commenced operations on 26 October 1993. | USA | AVCODES |
| 34 | J7 | Galaxy Airlines | ICAO: GXY, Callsign: Galax, Ceased Operations | J | AVCODES |
| 35 | J7 | Denim Air ACMI B.V. | ICAO: DNM, IATA designator changed to G6 | NL | AVCODES |
| 36 | J7 | Afrijet Business Services (ABS) | ICAO: ABS, IATA Prefix: 277, Name changed to Afrijet Business Services d/b/a Afrijet | G | AVCODES |
| 37 | J7 | Afrijet Business Services d/b/a Afrijet | ICAO: ABS, IATA Prefix: 277, Name changed from Afrijet Business Services (ABS). | G | AVCODES |
| 38 | J8 | Berjaya Air Sdn. Bhd. | ICAO: BVT, Callsign: Berjaya, | MAL | AVCODES |
| 39 | J9 | Guinee Airlines, S.A. | ICAO: GIF, Callsign: Guinee Airlines, | GUI | AVCODES |
| 40 | J9 | Jazeera Airways | ICAO: JZR, Callsign: Jazeera, Designator J9* reinstated by IATA | KWT | AVCODES |
| 41 | JA | Air Bosna | ICAO: BON, Callsign: Air Bosna, IATA Prefix: 995, Name changed to B & H Airlines June 2005. Suspended operations on 05 Septmeber 2003. Re-started | BIH | AVCODES |
| 42 | JA | Norways Airlines | ICAO: NOS, | N | AVCODES |
| 43 | JA | Regionair | ICAO: RGL, Callsign: Regair, Ceased operations in 1990. | GB | AVCODES |
| 44 | JA | Scimitar Airlines Ltd. | Declared bankrupt on 23 December 1981. | GB | AVCODES |
| 45 | JA | Jetair, Luftfahrt-Verwaltungsgellschaft | ICAO: JAG, Callsign: Jetair, | D | AVCODES |
| 46 | JA | Club Air | ICAO: CLS, Callsign: Irish Club, | IRL | AVCODES |
| 47 | JA | Jagson Airlines Limited | ICAO: JGL, Callsign: Jagson, | IND | AVCODES |
| 48 | JA | B & H Airlines | ICAO: BON, Callsign: BH Airlines, Suspended operations on 11 June 2015. Founded in 1994 as Air Bosna. Name changed in June 2005. | BIH | AVCODES |
| 49 | JA | JetSMART SpA | ICAO: JAT, Callsign: Rocksmart, | RCH | AVCODES |
| 50 | JA | Japanese Army | | J | TRAFFIC |
| 51 | JAA | Japan Asia Airways Co. Ltd. | IATA: EG, Callsign: Asia, IATA Prefix: 688, Ceased operations on 31 March 2008. | J | AVCODES |
| 52 | JAA | Jet Asia Airways Company Limited dba Jet Asia | IATA: JF, Callsign: Jet Asia, IATA Prefix: 884, Ceased operations during September 2020. | T | AVCODES |
| 53 | JAA | Japan Asia Airways | IATA: EG | | ICAO1 |
| 54 | JAA | Japan Asia Airways | | J | TRAFFIC |
| 55 | JAAC | JAMES MOVERS & STORAGE INC | | | SCAC4 |
| 56 | JAAD | J & A TRANSPORTATION LLC | | | SCAC4 |
| 57 | JAAJ | Järnvägssällskapet Åmål-Årjängs Järnväg | | SE | VKM |
| 58 | JAAL | JADE SKY LOGISTICS CORP | | | SCAC4 |
| 59 | JAAN | J A A R LLC | | | SCAC4 |
| 60 | JAAO | JUAREZ ALVARADO, ALFREDO | | | SCAC4 |
| 61 | JAAQ | JAAT TRANSPORT INC | | | SCAC4 |
| 62 | JAAR | JAMES GLOBAL LOGISTICS INC | | | SCAC4 |
| 63 | JAAT | JetAsia Airways | Real: JAA | T | TRAFFIC |
| 64 | JAAU | JORDAN BROMINE COMPANY LIMITED | | JOR | BIC |
| 65 | JAAU | JORDAN BROMINE COMPANY | | | PWRC |
| 66 | JAAU | Jordan Bromine | | | RSRV |
| 67 | JAAU | JORDAN BROMINE COMPANY LIMITED | | | SCAC4 |
| 68 | JAB | Juan Air (!979) Ltd. | Callsign: Juan Air, | CDN | AVCODES |
| 69 | JAB | Jet Business Airlines | Callsign: Jet Business, | B | AVCODES |
| 70 | JAB | Air Bagan Limited | IATA: W9, Callsign: Air Bagan, IATA Prefix: 017, Designator W9* recalled by IATA | MYA | AVCODES |
| 71 | JAB | Air Bagan Limited | Callsign: Air Bagan, Designator W9* recalled by IATA | MYA | AVCODES |
| 72 | JAB | Air Bagan | IATA: W9 | | ICAO1 |
| 73 | JABB | JOHAL NATIONAL INC | | | SCAC4 |
| 74 | JABC | J A B LOGISTICS INC | | | SCAC4 |
| 75 | JABE | JAMES CARTAGE CO INC | | | SCAC4 |
| 76 | JABH | JA-LYN FARMS LTD | | | SCAC4 |
| 77 | JABL | JACKSON TRANSPORTATION SERVICES INC | | | SCAC4 |
| 78 | JABM | J&B MURPHY TRUCKING, INC | | | SCAC1 |
| 79 | JABO | JAMERSON BROTHERS TRUCKING COMPANY | | | SCAC4 |
| 80 | JABP | JABEZ EXPEDITING & LOGISTICS CO | | | SCAC4 |
| 81 | JABQ | JAGRUP ENTERPRISES LTD | | | SCAC4 |
| 82 | JABR | J A B TRUCKING | | | SCAC4 |
| 83 | JAC | Japan Air Commuter Co. Ltd. | IATA: 3X, Callsign: Commuter, IATA designator changed to JC. | J | AVCODES |
| 84 | JAC | Japan Air Commuter Co. Ltd. | IATA: JC, Callsign: Commuter, IATA designator changed from 3X. | J | AVCODES |
| 85 | JAC | Japan Air Commuter | | | ICAO1 |
| 86 | JACC | JACKSON CARTAGE CO | | | SCAC1 |
| 87 | JACEK | PPHU Jacek Surdyk | | PL | VKM |
| 88 | JACF | J A C 'S EXPRESS LIMITED LIABILITY | | | SCAC4 |
| 89 | JACH | JAC | | | SCAC4 |
| 90 | JACI | JACINTO TRANSPORT | | | SCAC4 |
| 91 | JACJ | JTI TRANSPORTATION INC | | | SCAC4 |
| 92 | JACL | JACQUIN, CHARLES ET CIE INC | | | SCAC4 |
| 93 | JACN | JACOBSON TRANSPORT INC | | | SCAC4 |
| 94 | JACO | JACKSON, H L & SON | | | SCAC4 |
| 95 | JACS | JACKS TRUCKING LLC | | | SCAC4 |
| 96 | JACT | J A C TRUCKING LLC | | | SCAC4 |
| 97 | JACU | ALPHA SHIPPING AGENCY (PTY) LTD | | ZA | BIC |
| 98 | JACV | JACKSON OIL AND SOLVENTS INC | | | SCAC4 |
| 99 | JACW | JACOBSON, W TRUCKING | | | SCAC4 |
| 100 | JACX | Johnstown America Corp. | added 7/1992; 1/1994-7/2005 | | NAKINA |
