Duncansby Head is the most north-easterly part of both the Scottish and British mainlands, slightly northeast of John o’ Groats. It lies approximately 20 km (12 mi) east-southeast of Dunnet Head, the northernmost point of both the Scottish and British mainlands. Duncansby Head is located in Caithness, Highland, in north-eastern Scotland. The headland juts into the North Sea, with the Pentland Firth to its north and west and the Moray Firth to its south.

The Duncansby Head Site of Special Scientific Interest includes the 6.5-kilometre (4-mile) stretch of coast south to Skirza Head. It includes the Duncansby Stacks, prominent sea stacks just off the coast.