Railway administrator and politician. Dunbar was educated at the University of Edinburgh, graduating in 1828. In 1841 he succeeded his uncle to the Dunbar Baronetcy of Mochrum.
Dunbar was Deputy Chairman of the Edinburgh, Perth and Dundee Railway Company and was involved in their expansion in Fife and Kinross, together with their take-over by the North British in 1862. He was also involved in the development of the Portpatrick Railway in SW Scotland.
He served as Liberal Member of Parliament for the Wigtown Burghs (1857-65). He served in Palmerston's second administration as a Lord of the Treasury. He served as Comptroller-General of the Exchequer and Auditor-General of Public Accounts (1867-88).
Dunbar lived at Mochrum Park from 1879 and died there ten years later. He lies buried at All Saints, Challoch (Dumfries and Galloway).
