| Mecklenburg IX Mecklenburg G 3 | |
| Bgcolor: | FCC300 |
| Color: | 004A99 |
| Builddate: | 1887–1895 |
| Totalproduction: | 8 |
| Whytetype: | 0-6-0 |
| Driverdiameter: | 1350frac=8NaNfrac=8 |
| Over Bufferbeams: | 15176frac=4NaNfrac=4 |
| Axleload: | 13.31t |
| Serviceweight: | 39.94t |
| Weightondrivers: | 39.94t |
| Boilerpressure: | 10sigfig=3NaNsigfig=3 |
| Fireboxarea: | 1.53m2 |
| Evaporativearea: | 124.8m2 |
| Cylindercount: | Two |
| Cylindersize: | 450frac=16NaNfrac=16 |
| Pistonstroke: | 630frac=16NaNfrac=16 |
| Maxspeed: | 450NaN0 |
The Mecklenburg Class G 3 was an early German steam locomotive operated by the Grand Duchy of Mecklenburg Friedrich-Franz Railway. Formerly the Class IX it was a copy of the Prussian G 3.
In total, there were eight G 3 locomotives in the Mecklenburg fleet, which all built between 1887 and 1895. Of these two originally came from the Lloyd Railway, Neustrelitz - Warnemünde. The engines had a steam brake and an outside valve gear of the Allan type. Five engines were intended for transfer to the Deutsche Reichsbahn, to be numbered 53 7201 to 53 7205; however they were withdrawn before the renumbering plan was implemented.
The locomotives were given Class 3 T 10.5 tenders.