Of Muirfield and Gullane. Married (1748) to Lillias Steuart, daughter of Sir John Steuart, 2nd Bart of Allanbank, and Margaret Ker. A sometime woollen-draper in Edinburgh. Joint-manager (1762-1766), with Robert Herries (1730-1815), of Herries, Cochrane & Co. (the London branch of John Coutts & Co.) on Jeffrey Square.
Boswell described Cochrane as "a good, plain, comfortable Scots fellow; and his wife, though a lean existence, is a quiet civil being. He is entrusted by my father to pay me my allowance, and being his great friend, takes upon him to lecture me on my idle views of life."1
Cochrane is first mentioned in Boswell's journals on November 26, 1762, when Boswell went to see him in London to get his £25 allowance from home. Boswell met with Cochrane on several further occasions during his 1762-63 stay in London, including on May 15, 1763, when the two went together to hear Dr Blair preach.