Nathaniel Pigott (1725–1804) was an English astronomer, noted for his observations of eclipses, a transit of Venus and a transit of Mercury, and comets. He became a Fellow of the Royal Society on 16 January 1772, a foreign member of the Imperial Academy at Brussels in 1773, and a correspondent of the French Academy of Sciences in 1776.
Born in Whitton, Middlesex, Pigott was the son of Ralph Pigott of Whitton by his wife Alethea, daughter of the eighth Viscount Fairfax. He was the grandson of barrister Nathaniel Pigott (1661–1737), a Roman Catholic and intimate friend of poet Alexander Pope, who eulogised him in an epitaph inscribed in the parish church of Twickenham. The younger Nathaniel Pigott married Anna Mathurina, daughter of Monsieur de Bériol, and spent some years at Caen in Normandy for the education of his children. He and his family led a somewhat vagrant life in various parts of Britain and the Continent, where conditions were more congenial for the staunchly Catholic family.
It is not known when Pigott first became interested in astronomy. However, he was able to purchase fine instruments from London craftsmen and became known for observational ability and computational accuracy. The Academy of Sciences of Caen chose him a foreign member about 1764, and he observed there, with John Dollond's six-foot achromatic telescope, the partial solar eclipse of 16 August 1765. His observations of the transit of Venus on 3 June 1769 were transmitted to the French Academy of Sciences; his meteorological record at Caen, from 1765 to 1769, to the Royal Society, of which body he was elected a fellow on 16 January 1772. He maintained a friendly relationship with astronomer William Herschel.