Admiralty Bay () is an irregular bay, 8 km (5 mi) wide at its entrance between Demay Point and Martins Head, indenting the southern coast of King George Island (Antarctica) for 16 km (10 mi) in the South Shetland Islands. The name appears on a map of 1822 by Captain George Powell, a British sailor, and is now established in international usage.
A mariner's guide to the region pronounced the bay to have the best anchorage of any of the Shetlands, "being well-sheltered all around and having moderate depths over a bottom of good, stiff clay. Ice from the glaciers is frequently troublesome." [1]
The bay has three fjords: Martell, Mackellar, and Ezcurra.
The Henryk Arctowski Polish Antarctic Station is situated on the bay, as is the Comandante Ferraz Brazilian Antarctic Base.