Graemsay is an island in the western approaches to Scapa Flow, in the Orkney Islands of Scotland. The island has two lighthouses.
Geography and geology 
Graemsay lies between Hoy and Stromness on Mainland Orkney, separated from the Mainland by Clestrain Sound. The island is 409 ha (1.58 sq mi) in area and is mainly crofted.
The island's geology is old red sandstone of the Devonian period, with two volcanic faults. On the north coast there is granite-schist, a great rarity in Orkney.
Graemsay is surrounded by strong tidal races, known locally as roosts. An Orkney Ferries service links the island with Stromness and Moaness on Hoy.
Birds include oystercatchers, ringed plovers, redshank and curlew.
Parts of the island are largely undeveloped and are a haven for wild plants.
As with many other Orkney Islands, there is a connection to the Celtic Church, possibly a pre-Norse one. There are the remains of two early churches, dedicated to St Bride and to St Columba., who are both saints of Irish origin.
The island has two lighthouses, Hoy High (NE) and Hoy Low (NW), both built in 1851 by Alan Stevenson for the 19th century herring industry.
At the Point of Oxan in the far north west, in Burra Sound, are block ships, which were scuttled deliberately during World War II. This is a common feature of the straits/former straits around Scapa Flow
The school closed in 1996 and the island's children travel daily by boat to school in Stromness on the ferry 'Graemsay.'
There is a web site run by the current residents of Hoy High Lighthouse that gives a flavour of life today on Graemsay. http://www.graemsay.org.uk/index.htm The largest building, Sandside House, has been renovated and a website describing the property and the island is also of interest. http://www.graemsay.com Former residents of Graemsay and their descendants may find the web site run by Robert Whitton at http://www.robertwhitton.eu contains information about all Graemsay families.
Coordinates: 58°56′N 3°17′W / 58.933°N 3.283°W