[1] He was born on 25 August 1743,[2] the eighth son of Jean Maitland, only child of James, viscount Maitland, and grand-daughter of John, fifth earl of Lauderdale, and her husband, Sir James Fergusson, 2nd Baronet of Kilkerran in Ayrshire.
His elder brother was Sir Adam Fergusson, 3rd Baronet.
He was also appointed a lord justiciary on 4 August 1808, in the place of Sir William Nairne of Dunsinnam.
His portrait also appears along with those of the other judges in the 'Last Sitting of the Old Court of Session, 11 July 1808' (vol.
Fergusson married Graham (sic), daughter of William McDowall of Garthland, who survived him by several years.