Clan Gunn's ancestral tree is mixed in origin with the earliest know inhabitants of the area, the Picts. Later the Celts, Scots, Teutons, Normans, Norse and others integrated to extend the ancestral tree.

Practically without exception, the Highland Clans chiefly lines claim descent from the Norse Vikings. Clan Gunn is no exception; tracing its beginning to King Olaf the Black of Norway. The surname Gunn derives from Gun, Gunnar, or Gunni (depending upon the intepretation of historian) who was a grandson of Sweyn the Pirate of Freswick whose family ruled the earldoms of Orkney and Caithness during the 9th, 10th and 11th centuries.

The modern lineage and Sept families stem from George Gunn, the Crowner of Caithness, born in the first decade of the 15th century and slain with several of his clansmen at the Chapel of St. Tears, near Ackergil, in July 1478.

Clans have existed in many parts of the world but it was in the Highlands of Scotland that the clan system developed most fully as a way of life. It ended with the defeat of Bonnie Prince Charlie's Highlanders on the moors of Culloden, near Inverness, on April 16, 1746.

Following this defeat, the Clan system was abolished by law and for many years all weapons were forbidden to the Highlanders, as were the tartans, clan dress, clan symbols and paraphernalia, clan music and gatherings. Even the bagpipe was forbidden as it was considered an instrument of war.. At the same time a program known as the "clearances" was carried out with the stated objective of "clearing the Highlanders from the land to make it fit for the raising sheep". It was this program that was largely responsible for the scattering of the Highlanders to the far reaches of the world. When the proscription of the Clans was lifted and King George IV toured Scotland in the 1820's (he was the first monarch to visit Scotland in 175 years), he and his court were adorned in full Highland regalia. Tartans blossomed everywhere, the Clans were revitalized and Clan societies were organized in an attempt to re-establish family ties.