| Location Map: | Scotland Argyll and Bute |
| Caption: | Gigalum Island shown within Argyll and Bute |
| Coordinates: | 55.6495°N -5.7417°W |
| Gridreference: | NR6470145940 |
| Population: | 0 |
| Local Authority: | Argyll and Bute |
Gigalum Island or Gigalum is a tiny, private[1] uninhabited[2] island off the southeast coast of Gigha in Scotland.
Gigalum has a modern house in the middle, and gives its name to the strait between it and the main island, "Caolas Gigalum". There is also the "Gigalum Rocks" a reef to the east, and about 1miles north-northeast of Gigalum Island itself, "Sgeir Gigalum". It is also flanked by another islet, "Eilean na h-Uilinn", literally "Island of the Elbow".