Smith Island is long and wide, lying west of Deception Island in the South Shetland Islands of the British Antarctic Territory. It is separated from Snow Island by the Boyd Strait, and from Low Island by the Osmar Strait. Surface area is .
The discovery of the South Shetland Islands was first reported in 1819 by Capt. William Smith, after whom the island is named. This island was known to both American and British sealers as early as 1820, and the name Smith has been well established in international usage for over 100 years, although in Russian literature it is often referred to as Borodino Island, sometimes marked as Borodino (Smith) Island.
The island hosts no research stations or camps, and is seldom visited by scientists or mountaineers. Its interior is entirely occupied by the Imeon Range, rising to (Mount Foster). The first detailed topographic mapping of the island was made by the Antarctic Place-names Commission and the Military Geographic Service of the Bulgarian Army and published in 2009 in both English and Bulgarian.