Ramelton is situated at the mouth of the River Lennon, 11km north of Letterkenny and 4km east of Milford on the western shores of Lough Swilly. The town is named from Ráth Mealtain, 'the fort of Mealtan', an early Irish chieftain. The fort is said to lie under the ruins of a medieval castle of the O'Donnells, the ruling family of West Donegal before their exile to Europe in 1607.