| Sigma Islands | |
| Map: | Antarctica |
| Pushpin Map Caption: | Location in Antarctica |
| Location: | Antarctica |
| Archipelago: | Melchior Islands, Palmer Archipelago |
| Population: | Uninhabited |
| Country: | None |
| Treaty System: | Antarctic Treaty System |
The Sigma Islands are a group of small islands and rocks which lie 3disp=flipNaNdisp=flip north of Eta Island and mark the north limit of the Melchior Islands, in the Palmer Archipelago. The name, derived from the 18th letter of the Greek alphabet, appears to have been first used on a 1946 Argentine government chart following surveys of these islands by Argentine expeditions in 1942 and 1943.[1]