Gairsay is a small island in Orkney, Scotland, located in the parish of Rendall, 1.5mi off the coast, astride one of the approaches to the bays of Firth and Kirkwall. It is about 2mi long and 1mi wide and includes one conical hill and a small harbour called Millburn Bay, which is sheltered by the peninsula known as the Hen of Gairsay.