By his wife Elizabeth, a daughter of John Stewart, 1st Earl of Lennox, Argyll had issue:
Macallum left a widow, Euphemia, daughter of John Stewart of Glasgow, and one son.
His mother was Lady Caroline, daughter of John Stewart, 7th Earl of Galloway.
She was the daughter of John Stewart (MP).
DNB writes that he married Elizabeth Stewart, daughter of John Stewart, 1st Earl of Atholl on 19 January 1511.
He married as his second wife Lady Dorothea, daughter of John Stewart, 5th and last Earl of Atholl.
Marlborough married Lady Susan Stewart, daughter of John Stewart, 7th Earl of Galloway, on 15 September 1791.
While there Griffin married Christina Stewart, oldest daughter of John Stewart, the sixth Earl of Traquair (1699-1779).
Elizabeth was a daughter of John Stewart, 1st Earl of Lennox and Margaret Montgomerie.