Robert Ferguson FRS FRSE FGS (8 September 1769 – 3 December 1840) of Raith, was at various times a Whig Member of Parliament for Fifeshire, Haddingtonshire and Kirkcaldy Burghs, and at the time of his death he was Lord Lieutenant of the county of Fife.
As an amateur geologist and mineralogist the mineral Fergusonite was named after him.
Robert Ferguson was the eldest son of William Ferguson of Raith, Fife, and Jane Crauford, daughter of Ronald Craufurd of Restalrig, (sister to Margaret, countess of Dumfries). General Sir Ronald Craufurd Ferguson was his brother. He was educated at the High School in Edinburgh, 1777-1780. He was also privately tutored by John Playfair. He then studied Law at Edinburgh University. He qualified as an advocate in 1791.
Robert Ferguson was elected to the Whig parliament of 1806 for Fifeshire, but was not afterwards elected until the time of the Reform Bill, upon which he represented the Kirkcaldy district of Burghs from 1831 to 1835, and in the latter year was returned for Haddingtonshire, defeating Mr. Hope, the Tory candidate, by 268 to 231 votes. At the general election of 1837 he was in turn defeated by Lord Ramsay, who polled 299 votes to 205. He then returned to the representation of the Kirkcaldy division of Burghs. He was a cordial supporter of the measures of the Whig government, and opposed to the ballot.