The Lamonts trace their lineage to the ancient Kings of Ireland, possibly as early as 503AD. After the move to Scotland, various clan names preceded Lamont, the last being Lagman, grandson of Ferchar. The current name, however, is believed to come from the Lamon mor (Great Lamont) of tradition, the Sir Laumon of history, the benefactor of Paisley Abbey. Lamonts were the bearers of the lion arms and the green tartan, and were lords of all Cowal when it was virgin forest. Although not a large clan by comparison to their rivals, the Lamonts fared well and won fame in the Montrose campaigns of 1644-46. They did not, however, fight for the Bruce at Bannockburn in 1314 nor for Prince Charlie at Culloden in 1745. Law-abiding citizens, the Lamonts were loyal to the Crown and never fought against it from the 14th century onwards. Over time, they were decimated and beggared by their enemies; recovered for a period, they were then left landless by the improvidence of their chiefs. Few Lamonts remain in the ancient homeland of Argyllshire, and few structures remind one of this great period in history: the old kirk at Kilfinan with its crusaders' vaults, the ruins of the ancient Lamont home at Toward castle, and the Lamont Memorial in Dunoon where Lamonts were butchered by members of Clan Campbell after a peace agreement was struck in 1646.
Lamonts are a close-knit people, yet they have produced colonists who have spread their ilk to almost every corner of the world, leaving their marks and making the world a better place. They are known by different versions of Lamont, by septs who joined the Lamont chiefs and by names taken to hide their identities during the many problems at home. The chiefs of clan Lamont lived at Ardlamont until the last of their lands were sold in 1893 by the 21st chief, John Henry Lamont of Lamont, who emigrated to Australia. Around the time of the sale, Ardlamont was being rented out to hunting parties and lent its name to one of the most notorious Victorian murder mysteries, "The Arlamont Mystery". The present Chief of the Clan is Peter Noel Lamont of that Ilk, Chief of the Name and Arms of Lamont, who is a member of the Standing Council of Scottish Chiefs. The current chief is a parish priest in Marayong (a suburb of Sydney), New South Wales, Australia.