| Company | Search On | Records | Category | Sub category |
| Xetal Safety Glass Ltd | Xetal | 1 | Materials | Transparencies |
| Yacco | Yacco | 3 | Lubricant Suppliers | Oil |
| Yakolev | Yak | 22 | Aircraft Manufacturers | Non UK |
| Yeadon. Leeds Bradford | YeadonLeeds | 1 | Airfields | |
| Yorkshire Engineering Supplies Ltd | YES | 24 | Materials | Foundries |
| Y.Goldberg | YGoldberg | 1 | Manufacturing | Wood |
| Yorkshire Steel Co Ltd | YorkshireSteel | 6 | Components | Pyrotechnics |
| YSC Ltd (Holt Wingtip Flares) |
YSC | 15 | Manufacturing | Pyrotechnics |
| Zeiss (London) Ltd. Carl | Zeiss | 2 | Components | Electrical |
| Zenith Carburetter Co Ltd | Zenith | 25 | Components | Carburetters |
| Zimmerman. Motor Radiator Manufacturing Co | Zimmerman | 6 | Components | Radiators |
| Zwicky Limited | Zwicky | 136 | Ground Equipment | Refuelling |
