Calf of Man is a 2.50-square-kilometre island, off the southwest coast of the Isle of Man. It is separated from the Isle of Man by a narrow stretch of water called the Calf Sound. Like the nearby rocky islets of Chicken Rock and Kitterland, it is part of the parish of Rushen. It has only two seasonal inhabitants. The word 'calf' derives from the Old Norse word kalfr which means a small island lying near a larger one. It is possible to reach the Calf of Man by boat from both Port Erin and Port St Mary. Cow Harbour and South Harbour are the main landing places. The highest part of the island is in the west where an unnamed peak reaches 126 m above sea level.
Until 1939 the island was under private ownership by the Keig family, but the island was purchased by Mr F J Dickens of Silverdale, Lancashire who then donated it to the National Trust to become a bird sanctuary. In 1951 the Manx Museum & National Trust was established, which became known as Manx National Heritage. Manx National Heritage then rented the Calf from the National Trust for a nominal £1 per year until 1986, when ownership was transferred.