Eynhallow lies in Eynhallow Sound between Mainland, Orkney and Rousay. It is 75 hectares (0.29 sq mi) in area. An unnamed skerry is situated approximately 100 m (330 ft) to the north-east of the island, separated by Fint Sound. Sheep Skerry adjoins the southern end of the island.
There is no ferry to the island, although Orkney Heritage Society organises a trip each July. Otherwise, visitors have to arrange their own transport to the island by private local boat hire. Access can be problematic, as there are strong tidal surges in the surrounding strait, squeezed between Mainland of Orkney and Rousay.
It has its own folklore, concerning the initial finding of the island. Eynhallow was believed to be the summer residence of the shape-shiftingmer-people the Finfolk, who were driven away by the farmer, Guidman o' Thorodale from Evie.