The Clan Malcolm, also known as the Clan MacCallum, is a Highland Scottish clan. The Clan MacCallum may have originally been a separate clan until the 18th Century, when the chief of the Clan MacCallum adopted the name Malcolm after inheriting the Malcolm estate, and the two clans were drawn together under the same chief.

The name MacCallum is derived from Mac Ghille Chaluim which means son of the disciple of Columba. The MacCallums settled in Lorne towards the end of the 13th century.Maol or shavenhead is Scottish Gaelic for monk. Therefore Maol Chaluim can be translated as monk or disciple of Columba.

Historian Ian Grimble has challenged the idea that MacCallum and Malcolm are simply interchangeable versions of the same name. Grimble claims that Colm was common throughout all areas of Celtic settlement. The name Malcolm appears as a surname as early as the 14th century in Dumbartonshire and Stirlingshire. Malcolm was also the name of four Scottish kings.

In 1414 Ronald MacCaullum of Corbarron was appointed as constable of Craignish Castle.

In May 1562 Donald McGillespie Vich O'Challum received a charter of the lands of Poltalloch in the parish of Kilmartin in the county of Argyll from Duncan Campbell of Duntrune.

The Reverend Arhibald MacCallum translated parts of the Bible into Gaelic. In 1642 he succeeded his cousin to become the fourth Laird of Poltalloch. His son was Zachary MacCallum who was educated at the University of St Andrews and was also a noted swordsman.

Zachary's younger brother was Duncan whose son, Neil MacCallum served in the French Navy and is said to have been the natural father of Louis-Joseph de Montcalm. Zachary was a supporter of the Marquess of Argyll and he was killed in 1647 by forces of Sir Alexander MacDonald at Ederline. After killing seven of the enemy Zachary MacCallum turned to Sir Alexander MacDonald, who would have been his eighth that day if MacCallum was not taken from behind by an enemy(Maclean)who killed him with a Scythe.

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