| 3501 Class | |
| Powertype: | Steam |
| Designer: | William Dean |
| Builder: | Great Western Railway |
| Builddate: | 1885 |
| Ordernumber: | Lot 64 |
| Serialnumber: | 1006–1015 |
| Totalproduction: | 10 |
| Rebuilddate: | 1890–1891 |
| Numberrebuilt: | 5 |
| Whytetype: | (as built) (after rebuild) |
| Driverdiameter: | 5feet |
| Leadingdiameter: | 3feet |
| Wheelbase: | 17feet |
| Cylindersize: | 17x |
| Operator: | Great Western Railway |
| Operatorclass: | 3501 Class |
| Numinclass: | 10 |
| Withdrawndate: | 1892 |
| Disposition: | All converted to 3201 Class |
The GWR 3501 Class were ten broad gauge locomotives built by the Great Western Railway.
They were built in 1885 as locomotives, but five were rebuilt in 1890 as tender locomotives for working express trains between Exeter and Plymouth. They comprised the first ten locomotives of Lot 64, the remainder of which comprised ten similar locomotive Nos. 3511 to 3520 built to the standard gauge. In 1892 the broad gauge was abandoned and the locomotives were all converted to standard gauge tender locomotives, becoming a part of the 3201 Class.