Larkfield fort is a ringfort (rath) and National Monument located in County Longford, Ireland.

[2] On the Record of Monuments and Places it bears the code LF006-021----.

[3] Larkfield fort is located east of Lough Gowna, 500 m (1,600 ft) from the edge.

The nearest village is Mullinalaghta, 1.9 km (1.2 mi) to the southeast.

The ringfort is a univallate bank and ditch with an entrance in the east.