Letterkenny (Irish: Leitirceanainn, meaning “Hillside of the O’Cannons”) is the largest and most populous town in County Donegal, Ireland. It is also largest and tidiest urban centre in the north-west of the country. Its English name is derived from the Irish name Leitirceanainn, meaning “Hillside of the O’Cannons” – the O’Cannons being the last of the ancient chieftains of Tír Conaill. With a population of 19,588, Letterkenny is located on the River Swilly in east Donegal.