Castletown (Scottish Gaelic: Baile a' Chaisteil) is a village on the north coast of the Highland council area of Scotland, situated near Dunnet Bay.

The name Stanergill can be read as meaning Stone Valley and much of Castletown was built during the 19th century boom years of Caithness as a source of flagstone.

Much of the stone was processed in the harbour area of the village, known as Castlehill, and many of the streets of London, Sydney, Edinburgh and the financial district of New York City are paved with it.

The building that was used for these functions was the 'Traill Hall', a gift to the Village by the Traill family, owners of the flagstone quarry at Castlehill.

Castletown has a small hotel (The Castletown Hotel, was The St Clair Hotel), a large bed and breakfast on a large property (Olrig House Country B&B), a large guest house (Greenland House), a licensed grocery, a butcher's, a fish and chip shop, a garden centre, a garage, hairdressers, a primary school with nursery and an after-school club, a drill hall, a youth club and an army cadets detachment hut.