Coquet Island is a small island of about 6 hectares (fifteen acres), situated 1.2 km off Amble on the Northumberland coast. It is owned by the Duke of Northumberland. The Royal Society for the Protection of Birds manages the island as a bird reserve, for its important seabird colonies.

The lighthouse was built to the design of James Walker. The white square tower is of sandstone surrounded by a turreted parapet with walls in excess of one metre thick. The dwelling houses are also an integral part of the fortress-like structure where the keepers appointed to attend the light lived during their periods on duty. It was in fact the remaining structure of a medieval monastery, home to St. Cuthbert, which was largely incorporated into the 19th-century lighthouse and lighthouse keepers' cottages.

The lighthouse, operated by Trinity House, is now automatic with no resident keeper, so the island is uninhabited in winter, but seasonal wardens are present throughout the summer to protect the nesting birds.

The first keeper appointed to Coquet lighthouse was William Darling, elder brother of Grace Darling. He was in fact the second of her brothers to become a keeper in the Trinity House Service. It has been said that it was probably a boat trip to see her brother at Coquet Island in the summer of 1842 that led to a chill which eventually proved fatal to her. In fact Grace Darling died from tuberculosis ("consumption").