The River Finn is a river in the west of Ulster, the northern province in Ireland. The river mainly flows through County Donegal, part of the Republic of Ireland, while a short stretch of the river also partially flows through County Tyrone, part of Northern Ireland. From Lough Finn, the river goes to Ballybofey and Stranorlar before joining the River Mourne at Lifford and Strabane.

Lifford is the county town of County Donegal, Ireland, the administrative centre of the county and the seat of Donegal County Council, although the town of Letterkenny is often mistaken as holding this role.