Gigha is six miles long and a mile and a half wide at its widest, lying four miles west of the Kintyre coast. The highest point, Creag Bhan, reaches only 330 feet, which by Hebridean standards is more a hill than a mountain. Geologically the island is mostly amphibolite, a metamorphic rock cut by Palaeogene dykes from the same volcanic event that produced the Giant's Causeway and Staffa. The climate is unusually mild for the latitude - higher than average sunshine hours, fewer ground frosts than most of mainland Scotland. The main settlement is Ardminish on the southeast coast, where the Caledonian MacBrayne ferry from Tayinloan docks. The single road runs the length of the island. There are scattered farms, an Ayrshire dairy herd, a halibut fish farm at South Druimachro, the Achamore Gardens at the island's centre, and a primary school. Secondary school pupils go to the mainland. There is a post office, a shop, a hotel, and a strong local feeling that the island should be a place where children can grow up and stay if they want to.

The island's name has resisted all attempts at clean etymology. The Norse saga Hakonar Saga Hakonarsonar calls it Gudey, suggesting an Old Norse origin meaning either the god's island or Gydha's island. Other readings reach further back to a pre-Norse Gaelic origin - possibly the sheela na gig, a female fertility figure - and a 1309 charter records the place as Gug. The name appears as Gega on some old maps. What is clear is that Gigha has been continuously inhabited since prehistoric times. There are several standing stones, multiple cairns and duns, and an ogham stone near Kilchattan that nobody has yet been able to decipher. The Cenel nGabrain, the Gaelic kingdom that dominated Kintyre and the southern Hebrides in the early Middle Ages, may have used Gigha as a seat of power; the Annals of Tigernach record a Battle of Delgon here in 574, possibly during the reign of Conall mac Comgaill, King of Dalriada. The Norse came, settled, gave the island a name that may or may not be theirs. A 1849 Viking grave at East Tarbert Bay yielded a tenth-century bronze weighing balance. There are Norse names dotted across the surrounding islands: Gigalum, Cnoc Haco - perhaps Haakon's hill, after the king who is said to have stopped here on his way to the disastrous Battle of Largs in 1263.

Gigha is the ancestral home of Clan MacNeill - distinct from, though sharing a chief with, the better-known Clan MacNeil of Barra. The MacNeills of Taynish, Gigha, and Colonsay served as hereditary keepers of Castle Sween under the Lords of the Isles in the fifteenth and sixteenth centuries. In 1449 Alexander, Lord of the Isles granted part of Gigha to Torquil MacNeill of Taynish; by 1493 the whole island was MacNeill territory. None of this protected the islanders. In 1530 the notorious pirate Ailean nan Sop murdered the MacNeill of Taynish and a number of island residents. Twelve years later a raid killed eleven men of Gigha and burned the title deeds. In the late sixteenth century Lachlan Mor MacLean of Duart attacked the MacDonald islands of Islay and Gigha; chroniclers record 500 to 600 men killed in the violence, though such numbers from the period are often exaggerated. By 1590 the Campbells were sweeping up MacDonald lands across the western seaboard, and Angus MacDonald of Islay sold Gigha to John Campbell of Cawdor in what may have been a pre-arranged Campbell consolidation. The island then went through Scarlett, Allen, Hamer, de Chair, and Horlick hands in the twentieth century. Generations of islanders learned that the land beneath their feet did not belong to them.

Three Vestas V27 wind turbines stand on a low ridge near the centre of Gigha. Commissioned on 21 January 2005 by the islanders themselves through Gigha Renewable Energy Ltd, they have a combined capacity of 675 kilowatts. The locals call them The Dancing Ladies, or in Gaelic Creideas, Dochas is Carthannas - Faith, Hope, and Charity. The electricity is sold to the grid via an intermediary company; the profits are reinvested in the Heritage Trust's projects. Two batteries were added in 2016 to smooth output and let the island store overnight wind power. The Dancing Ladies are not the largest wind farm in Scotland by a long margin - several offshore developments produce more energy in a few hours than the Gigha turbines produce in a year - but they are entirely community-owned, and the revenue cycle is small enough that islanders can see what their wind is paying for. A new house. A new road surface. A community hall extension. Some of the dairy cattle returning. Three turbines, 187 people, the recovery of an island. None of it would have been possible without the buyout in 2002. Most of it would not have happened without the Atlantic wind that has been hammering this coast since long before Gigha had a name.