This section of LocomotivesUK Encyclopedia is for covering Diesel Locomotives in the UK.
| Diesel Mechanical | Diesel Hydraulic | Diesel Electric | Diesel Engines |
| Class 01 | Class 02 | Class 03 | Class 04 |
| Class 05 | Class 06 | Class 07 | Class 08 |
| Class 09 | Class 10 | Class 11 | Class 12 |
| Class 13 | Class 14 | Class 15 | Class 16 |
| Class 17 | Class 20 | Class 21 (v1.0) | Class 21 (v2.0) |
| Class 22 | Class 23 | Class 24 | Class 25 |
| Class 26 | Class 27 | Class 28 | Class 29 |
| Class 31 | Class 33 | Class 35 | Class 37 |
| Class 40 | Class 41 (v1.0) | Class 41 (v2.0) | Class 42 |
| Class 43 (HST) | Class 44 | Class 45 | Class 46 |
| Class 47 | Class 50 | Class 52 | Class 55 (Deltic) |
| Class 56 | Class 57 | Class 58 | Class 59 |
| Class 60 | Class 66 | Class 67 | Class 68 |
| Class 69 | Class 70 (v2.0) | Other UK Diesels | |
