Myths about the island include the story of the Copinsay Brownie.
For many generations, prior to the final inhabitants moving to the Mainland in 1958, Copinsay was full of life; the large, double storey farmhouse and behind it the Steading for the farm tenants, a school with a schoolteacher and up to three lighthouse keepers' families.
There is also an ancient burial site on the island.
In the earlier part of the 20th century, a weekly postal service provided contact with the Mainland and fortnightly shopping trips to Deerness, allowing for weather. The farm boasted working horses, cattle and sheep - all of which had to be transported on the "coo" or "cow" boat. Birds' eggs provided a good supplement to the islanders' diet, and men were lowered over the cliffs on a special rope, or rowed out to the Horse to bring back this addition.
Pigs were loosed in the spring on the Horse for many years - feeding on the bird eggs - transported across the sound by boat.
Many interesting facts and accounts of life on Copinsay are still retold in the Deerness Community, with many members still remembering when the island was still home to loved ones.
The island was bought by the ornithology charity, the RSPB in 1972 in memory of the naturalist James Fisher. Although Copinsay today is uninhabited, some fields are still farmed at the behest of the RSPB, to try provide suitable conditions for Corncrake, so the patch work of yesteryear is returning to the island, even though the people have not. Together with the three adjacent three islets (Corn Holm, Ward Holm and Black Holm), it is designated a Special Protection Area (SPA) under the European Union directive on the Conservation of Wild Birds due to the unimproved grassland vegetation and sheer sandstone cliffs providing ideal breeding ledges for seabirds. There is a large colony of grey seals on the island. They usually pup in November each year. Puffins can be seen during July on the adjacent holms.
Edwin Muir, a famous poet