The Douglases of Mains are a branch of the Clan Douglas, related to the Lords of Douglas through Archibald I, Lord of Douglas. The first Laird obtained land through marriage into the Galbraith family, which had been granted land in New Kilpatrick by Maldowen, Earl of Lennox. The family produced minor nobles in the Scottish court, perhaps the most notable of which was Malcolm Douglas, the 8th Laird, executed for treason in Edinburgh for conspiracy in the Raid of Ruthven. His second son, Robert Douglas, was made Viscount of Belhaven and is buried in Holyrood Abbey. The family intermarried in the Glasgow area, having links with the Campbells of Blythswood, with landed families across Scotland and more latterly the United Kingdom. The title became extinct in the 20th century; the last 33+1⁄2 acres of the estate was sold to Dunbartonshire county and was subsequently used for the erection of the secondary school, Douglas Academy, in Milngavie prior to the death of the last heir in 1977.

Clan Douglas is an ancient clan or noble house from the Scottish Lowlands.