Born at Dumbarton, Silver Banks, he was the son of Archibald Edmonstone, 10th of Duntreath, and his wife Anne Campbell (d Ireland, 2 November 1785, paternal granddaughter of Archibald Campbell, 9th Earl of Argyll and maternal granddaughter of John Elphinstone, 8th Lord Elphinstone and sister of the John Campbell, 4th Duke of Argyll).
He was Gentleman Usher of the Black Rod in Ireland from 1763 to 1765. He succeeded his father in 1768. In 1780 he was chosen for Ayr Burghs but was again Member for Dumbartonshire in 1790, and continued to hold this office until he retired from Parliament in 1799.
A staunch Tory supporter, he upheld Lord North"s government during the American War of Independence, and due to his public services, he was created a baronet on 20 May 1774.
Edmonstone, having lived to be eighty nine, died in his house in Argyll Street in London in July 1807.
12th Parliament of Great Britain. 13th Parliament of Great Britain. 14th Parliament of Great Britain.
15th Parliament of Great Britain.
16th Parliament of Great Britain. 17th Parliament of Great Britain]
By the time of his inheritance he was Member of Parliament for the Dumbartonshire, to which seat he was elected in 1761, 1768, and 1774.
