| Great Northern Railway Class BT | |
| Powertype: | Steam |
| Designer: | J.C. Park |
| Builddate: | 1885 |
| Totalproduction: | 13 |
| Driverdiameter: | 4feet |
| Boilerpressure: | 1602NaN2 |
| Cylindercount: | Two, inside |
| Cylindersize: | 15x |
| Trainheating: | steam |
| Operator: | GNR(I) |
| Numinclass: | 13 |
Great Northern Railway Class BT were a class of 13 tank locomotives introduced by the GNR(I) from 1885.
While fit for purpose when built, increasing train weights particularly with bogie carriages a factor meant by the 1920s they were underpowered for all available work and were withdrawn by 1921.