The island has been known by various names over the years. Early records and maps mention it as St Michael's Island. The name later changed to Borough Island, eventually shortened to Burgh.
It is believed a monastery was established on the island, most of the remains of which may lie beneath the current hotel. The ancient Pilchard Inn may have started life as the guest lodgings for the monastery.
A small, perhaps transient, population of fishermen occupied the island following the dissolution of the monasteries. There are the remains of a chapel stop the island, which later became a huers hut, a place where fishermen would make a 'hue and cry' call to inform other fishermen of shoals of pilchards.
Burgh Island is closely linked to Agatha Christie, as it served as the inspirational setting for Soldier Island and for the setting of Evil Under the Sun.