Historian. Born at Borthwick (Midlothian) and educated in Dalkeith and at the University of Edinburgh, where he studied divinity. He became minister at Gladsmuir (East Lothian) in 1743 and later at Lady Yester's Kirk and Greyfriars in Edinburgh. He volunteered to defend the city against the Jacobites led by Prince Charles Edward Stuart in 1745.
He became Royal Chaplain to King George III (1761), Principal of the University of Edinburgh (1762) and Royal Historiographer (1764). His most notable work was perhaps his History of Scotland 1542 - 1603 (1759).
Robertson is buried at Greyfriars Kirkyard in Edinburgh. The William Robertson Building on the George Square campus of the University of Edinburgh is named in his honour.