Kintyre, like Knapdale, contains several Stone Age sites; at Ballochroy is a trio of megaliths aligned with land features on the island of Jura, while a number of burial cairns still stand at Blasthill (near Southend, Argyll).

The history of the presumed Pictish inhabitants of Kintyre is not recorded, but a 2nd-century BC stone fort survives at Kildonan (near Saddell), and it is not implausible that they continued to use Dun Skeig.

Sanda, an island adjacent the south coast of Kintyre, is strongly associated with Ninian, the first known missionary to the Picts, and contains an early 5th century chapel said to have been built by him.

In 563, Columba arrived in Kintyre, to pay his respects to the kings of Dal Riata, before continuing to Iona, where he established a base for missionary activity throughout the Pictish regions beyond.

Dál Riata was ultimately destroyed when Norse Vikings invaded, and established their own domain, spreading more extensively over the islands north and west of the mainland.

The unspecific wording led Magnus to have his boat dragged across the narrow isthmus at Tarbert, while he rode within it, so that he would thereby acquire Kintyre, in addition to the more natural islands of Arran and Bute.

In the mid 12th century, Somerled, the husband of Godred Crovan's granddaughter, led a successful revolt against Norway, transforming Suðreyjar (including Kintyre) into an independent kingdom.

In 1266, his more peaceable successor ceded his nominal authority over Suðreyjar to the Scottish king (Alexander III) by the Treaty of Perth, in return for a very large sum of money.

Although Alexander III generally acknowledged the semi-independent authority of Somerled's heirs, he did not give them back control of the mainland territory which Scottish forces had taken during the strife, including parts of Kintyre.

After 4 years and 3 children, however, he divorced Amy, and married Margaret, the daughter of Robert II, the Scottish king, who gave him the remaining parts of Kintyre, along with the whole of Knapdale, as a dowry.

In 1462, however, John, the then Lord of the Isles, plotted with the English king to conquer Scotland; civil war in England delayed the discovery of this for a decade.

Upon the discovery, in 1475, there was a call for forfeiture, but a year later John calmed the matter, by quitclaiming Ross (Easter, Wester, and Skye), Kintyre, and Knapdale, to Scotland.