Castletown (Scottish Gaelic: Baile a' Chaisteil) is a village on the north coast of the Highland council area of Scotland, situated near Dunnet Bay. It is within the civil parish of Olrig, where it is the main settlement, and within the historic county of Caithness. The A836 links the village with Thurso and Tongue in the west and with John o' Groats in the east. The B876-A99 links the village with Wick in the southeast. Much of the village is built on the old townland (or fermland) of Stanergill. The Stanergill Burn was the eastern boundary of the townland. It flows now through the eastern end of the village and so into Dunnet Bay and the Atlantic Ocean.