| ST45 | |
| Powertype: | Diesel |
| Builder: | PESA Bydgoszcz SU45s built by Cegielski |
| Builddate: | 2009 |
| Uicclass: | Co′Co′ |
| Driverdiameter: | 1,100 mm |
| Length: | 18,990 mm |
| Width: | 3,900 mm |
| Height: | 4,288 mm |
| Enginetype: | MTU 4000 |
| Cylindercount: | 12 |
| Transmission: | Electric |
| Poweroutput: | 1500kW |
| Locobrakes: | Oerlikon |
| Operator: | PKP |
| Operatorclass: | ST45 |
| Numinclass: | 4 |
| Fleetnumbers: | ST45-01—ST45-04 |
| Deliverydate: | 2009 |
ST45 is the name for a Polish diesel locomotive. They are freight only locomotives, having had their train heating removed.
These locomotives are SU45s with replacement engine and no train heating facilities. During 2009-2010 4 locomotives were rebuilt to class ST45.