Stonington Island was chosen as the site for the East Base of the United States Antarctic Service (USAS) Expedition (1939–41).

It was named after Stonington, Connecticut, home port of the sloop Hero in which Captain Nathaniel Palmer sighted the Antarctic continent in 1820.

[4][5] A protected area on the island consists of the buildings and artifacts at East Base (with their immediate environs) that were erected and used during the two US wintering expeditions.

[7] On 22nd December 2022, two British citizens, Caius and Rosie, traveling on board the expedition cruise ship Greg Mortimer were legally married in a simple ceremony conducted by a Marriage Officer appointed by the Commissioner of the British Antarctic Territory, becoming the first people in history to be married at Stonington Island.

A circular, 500 ha site on the island has been designated an Important Bird Area (IBA) by BirdLife International because it supports a breeding colony of about 135 pairs of imperial shags.