| Belgian State Railways Type 12 | |
| Powertype: | Steam |
| Builddate: | 1888–1897 |
| Totalproduction: | 115 |
| Uicclass: | 1B1 n2 |
| Fireboxtype: | Belpaire |
| Cylindercount: | Two, inside |
| Valvegear: | Walschaert |
| Operator: | Belgian State Railways |
| Operatorclass: | Type 12 |
The Belgian State Railways Type 12 was a class of steam locomotives for express passenger service, introduced in 1888. They were the successors of the Belgian State Railways Type 1 locomotives.
The locomotives were built by various manufacturers from 1888 to 1897.The machines had an outside frame with the cylinders and the Walschaert valve gear located inside the frame.
The locomotives used three-axle tenders with a capacity, as well as two-axle tenders with .
| 28 | 1885–1888 | Belgian State Railways | ||
| 12 | Belgian State Railways | |||
| 15 | 1891–1896 | Belgian State Railways | ||
| 10 | Belgian State Railways | |||
| 5 | 1893–1895 | Belgian State Railways | ||
| 13 | 1892–1897 | Belgian State Railways | ||
| 14 | 1888–1898 | Belgian State Railways, one with Durant-Lencauchez valve gear | ||
| 8 | Belgian State Railways |