The name dates back to at least 1820 and is now established in international usage, except for Russia, where it has been known as Shishkova Island since its discovery by the First Russian Antarctic Expedition in 1821.

The island is 21.46 km (13.3 mi) long and oriented in a south-southwest to north-northeast direction.

The summit Mount Irving, 1,950 meters (6,398 ft) high,[1][2] rises 6.675 km (4.148 mi) north of Cape Bowles, the southernmost point.

The southeast slopes of the two ridges are drained by Dobrodan, Highton, Treskavets, Orcho, and Banari Glaciers, and their northwest slopes — by Skaplizo, Giridava, and Bersame Glaciers.

[3] Antarctic explorer Ernest Shackleton's Imperial Trans-Antarctic Expedition observed and considered landing on Clarence Island after escaping the pack ice of the Weddell Sea but instead landed on the nearby Elephant Island.