Robert Fullarton Udny or Udney (1725–1802) was a Scottish merchant, art collector and Fellow of the Royal Society.
[9] He inherited property at Dudwick, Aberdeenshire in 1786 on the death of Robert Fullerton, a soldier of fortune and cousin.
[18] In July 1786 George Romney, John Flaxman, Jeremiah Meyer and William Hayley visited Udny's collection at Teddington.
[19] In the 1790s the Udnys were on good terms with Ozias Humphrey, though Robert took against a portrait he had painted of his wife.
[20] The Burlington House Cartoon by Leonardo da Vinci was acquired by Udny from Italy in 1763, before passing to the Royal Academy.
[21] Before 1799, Udny had sent to Catherine the Great two other da Vinci cartoons, drawings of heads from his work The Last Supper.
[4][26] The compensation for the Grenada estate under the Slavery Abolition Act 1833, of £7,972, was paid to Temperance Udny.
[27] Udny's wish, that the Royal Academy should be given a first option to purchase his collection, was respected by his executors, but no sale resulted.