A summer colony, the island is located in the northeast part of Mathews County, south of the mouth of the Piankatank River.

In 1642, Hugh Gwynn of Jamestown purchased the island; he and his family became the first English settlers there.

[1] In 1776, Gwynn's Island served as a base for Lord Dunmore, the last royal governor of Virginia, after the Burning of Norfolk.

A smallpox outbreak and attacks by the revolting patriots led Dunmore to leave the island in the summer of 1776.

[2] During the attacks on Gwynn's Island in July 1776, the only casualty on the side of the revolutionaries was one Captain Dohickey Arundel, commander of two eighteen-pound cannons, who attempted to fire an experimental wooden mortar of his own invention, "though the general and all the officers were against his firing it".