Buncrana is a town in County Donegal, Ireland. It is beside Lough Swilly on the Inishowen peninsula, 23 kilometres northwest of Derry and 43 kilometres north of Letterkenny. In the 2022 census, the population was 6,971, making it the second most populous town in County Donegal, after Letterkenny, and the largest in Inishowen. Buncrana is the historic home of the O'Doherty clan and originally developed around the defensive tower known as O'Doherty's Keep at the mouth of the River Crana.