| Company | Search On | Records | Category | Sub category |
| Jablo Propellers Ltd | Jablo | 54 | Components | Propellers |
| J.Ackworth & Co | JAckworth | 1 | Engineering Equipment | Machine Tools |
| Jacobs Aircraft Engine Co | Jacobs | 2 | Engine Manufacturers | Non UK |
| Jacobs Young & Co Ltd.M. | JacobsYoung | 1 | Materials | Wood |
| Jacques Wolf | JacquesWolf | 2 | Gases | Hydrogen |
| James Means | JamesMeans | 4 | Components | Controls |
| James Bartle & Co | JamesBartle | 1 | Components | Electrical |
| James Beresford & Son Ltd | JamesBeresford | 1 | Components | Toilets |
| James Briggs & Sons | JamesBriggs | 1 | Health And Safety | Dermatitis |
| James & Browne Ltd | JamesBrowne | 1 | Engine Manufacturers | |
| James Carr & Sons Ltd | JamesCarr | 1 | Manufacturing | Textiles |
| James Clews & Sons Ltd | JamesClews | 3 | Manufacturing | Components |
| James Davies | JamesDavies | 2 | Engine Manufacturers | |
| James Means | JamesMeans | 4 | Components | Controls |
| James Neill & Co | JamesNeill | 2 | Engineering Equipment | Hand Tools |
| James North Hardy & Son Ltd | JamesNorthHardy | 2 | Materials | Fabric |
| James Putnam | JamesPutnam | 3 | Structures | Tents |
| James Strang & Sons | JamesStrang | 1 | Lubricant Suppliers | |
| James Talbot & Davison (1916) Ltd | JamesTalbot | 1 | Manufacturing | Pistons |
| James Walker & Co Ltd | JamesWalker | 14 | Components | Seals |
| James Williamson & Son | JamesWilliamson | 1 | Manufacturing | Flooring |
| James Wooley, Sons & Co Ltd | JamesWooley | 1 | Health And Safety | First Aid Kits |
| J.A.P. John A.Prestwich | JAP | 17 | Engine Manufacturers | |
| J.A.T.Yugoslav Airlines | JAT | 1 | Air Transport | Airlines |
| J B Brooks & Co Ltd | JBBrooks | 36 | Materials | Leather |
| J,B.Carr | JBCarr | 2 | Airfields | Construction |
| J.B.Guthrie & Son | JBGuthrie | 1 | Manufacturing | AGS |
| J.Bonn & Co Ltd | JBonn | 26 | Manufacturing | Castings |
| J.D.Beardmore & Co Ltd | JDBeardmore | 2 | Manufacturing | Presswork |
| Jenks Bros Ltd | JenksBros | 8 | Engineering Equipment | Hand Tools |
| Jenks & Cattell Ltd. A.E. | JenksCattell | 9 | Manufacturing | Presswork |
| Jennings, Guilding & Company | JenningsGuilding | 3 | Manufacturing | Sheet Metal Work |
| Jenolite Ltd | Jenolite | 5 | Chemicals | Paint Spraying |
| Jenson & Nicholson Ltd | JensonNicholson | 2 | Finishes | Paints |
| Jeppesen & Co | Jeppesen | 24 | Pilot Supplies | Charts |
| Jersey Airways | JerseyAirways | 6 | Air Transport | Airlines |
| JetFlex. Power Flexible Tubing Co | Jetflex | 2 | Components | Tubing |
| Jetstream Aircraft Ltd | JetstreamAircraft | 2 | Aircraft Manufacturers | |
| Jet Tanks Limited | JetTanks | 6 | Manufacturing | Fibre Glass |
| Joseph Evans & Co Ltd | JEvans | 2 | Manufacturing | Airframe |
| J.F. Airlines Ltd | JFA | 1 | Air Transport | Airlines |
| J.F. Bardolph & Partners Ltd | JFBardolph | 4 | Fasteners | Clamps |
| J.F.Kenure Ltd | JFKenure | 2 | Manufacturing | Components |
| J.F.Ratcliff (Metals) Ltd | JFRatcliff | 4 | Materials | Rolled Metal |
| J.Gerber & Co Ltd | JGerber | 1 | Factory | Electrical |
| J.Gliksten & Son Ltd | JGliksten | 5 | Materials | Wood |
| J H Randall & Son Ltd | JHRandall | 12 | Fabrication | Sheet Metal Work |
| J.J.Benson Aircraft Interior Furnishing Ltd | JJBenson | 4 | Role Equipment | Cabin Furnishings |
| J.J.Johnston & Co Ltd | JJJohnston | 1 | Vehicles | Snow Clearance |
| J.L.Jameson Ltd | JLJameson | 1 | Manufacturing | Jigs |
| J.Moss | JMoss | 7 | Clothing | Uniforms |
| J.M.Steel & Co Ltd | JMSteel | 7 | Finishes | Paints |
| Jones & Co. Jno. | JnoJones | 1 | Factory | |
| J.N.Somers Ltd | JNSomers | 1 | Components | Electrical |
| James A.Jobling | Jobling | 8 | Airfields | Lighting |
| John Bass Ltd | JohnBass | 2 | Ground Equipment | Cleaning Tools |
| John E.Clarke & Co Bournemouth Ltd | JohnClarke | 2 | Fixtures and Fittings | Interiors |
| John Cox & Son Ltd | JohnCox | 15 | Materials | Textiles |
| John Dale Ltd | JohnDale | 2 | Manufacturing | Castings |
| John Dawson & Company | JohnDawson | 7 | Aeronautical Engineers | |
| John F.Cox & Co | JohnFCox | 3 | Engineering Equipment | Jig & Patternmakers |
| John Hamilton Ltd | JohnHamilton | 1 | Literature | Publishers |
| John Holroyd & Co Ltd | JohnHolroyd | 1 | Manufacturing | Castings |
| John Lane Bodley Head Ltd | JohnLane | 1 | Literature | Publishers |
| John Marston Ltd | JohnMarston | 2 | Manufacturing | Sheet Metal Work |
| John Martin & Co | JohnMartin | 2 | Materials | Curled Hair |
| John McClure Ltd | JohnMcClure | 1 | Manufacturing | Assemblies |
| John Mills & Co | JohnMills | 1 | Manufacturing | Engineering Machinery |
| John Ormerod & Sons Ltd | JohnOrmerod | 1 | Materials | Leather |
| John Remer & Co | JohnRemer | 3 | Suppliers | Wood |
| John Rigby & Sons | JohnRigby | 7 | Aeronautical Engineers | AGS |
| John Shaw Ltd | JohnShaw | 1 | Manufacturing | Cables |
| John Shaw & Sons (Salford) Ltd | JohnShawSons | 1 | Manufacturing | Machine Tools |
| Johnson Bros. G. | JohnsonBrosG | 14 | Communications | Heaters |
| Johnson & Johnson (Great Britain) Ltd | JohnsonJohnson | 20 | Finishes | Masking Tape |
| Johnson & Phillips Ltd | JohnsonPhillips | 28 | Factory | Electrical |
| Johnson, Taylor & Co | JohnsonTaylor | 2 | Office | Office Equipment |
| John Wrights & Co | JohnWright | 4 | Engineering Equipment | Furnaces |
| John Wright & Sons (Veneers) Ltd | JohnWrightVeneers | 2 | Materials | Veneers |
| Jonas & Colver Ltd | JonasColver | 7 | Manufacturing | Steel |
| Jones Bros & Co Ltd | JonesBros | 3 | Manufacturing | Pressings |
| Jones Ltd. A E | JonesModels | 1 | Models | Rubber |
| Joseph Evans & Co Ltd | JosephEvans | 2 | Manufacturing | Components |
| Joseph Freeman, Sons & Co Ltd | JosephFreeman | 4 | Finishes | Paints |
| Joseph Gillott & Sons | JosephGillott | 4 | Materials | Steel |
| Joseph C. Mount | JosephMount | 2 | Logistics | Shippers |
| Joseph Owen & Sons Ltd | JosephOwen | 10 | Materials | Wood |
| Joseph Rodgers & Sons Ltd | JosephRodgers | 1 | Manufacturing | Engineering |
| Joshua Bigwood & Son Ltd | JoshuaBigwood | 2 | Engineering Equipment | Machinery |
| J.Parkinson & Son | JParkinson | 1 | Engineering Equipment | Vices |
| J.Rhodes & Sons | JRhodes | 4 | Engineering Equipment | Machinery |
| J.R. Staines & Partners Ltd | JRStaines | 5 | Manufacturing | Consultancy |
| J.Stone & Co (Charlton) Ltd | JStone | 29 | Materials | Foundries |
| J Thorn & Sons Ltd | JThorn | 1 | Structures | Hangars |
| J.T.Lunt | JTLunt | 3 | Suppliers | Merchants |
| Julius Sax & Co Ltd | JuliusSax | 1 | Components | Electrical |
| Junkers-Flugzeugwerk | Junkers | 24 | Aircraft Manufacturers | Non UK |
| J.V.Rushton | JVRushton | 36 | Materials | Anodising |
| James W.Carr & Co | JWCarr | 3 | Engineering Equipment | Machine Tools |
| J & W Mitchell Ltd | JWMitchell | 3 | Engineering Equipment | Drafting |
