Henri Grégoire (French pronunciation: [ɑ̃ʁi ɡʁeɡwaʁ]; 4 December 1750 – 20 May 1831), often referred to as Abbé Grégoire, was a French Roman Catholic priest, constitutional bishop of Blois and a revolutionary leader. He was an ardent abolitionist and supporter of universal suffrage, and was a founding member of the Bureau des longitudes, the Institut de France, and the Conservatoire national des arts et métiers.

He was born at Vého near Lunéville, the son of a tailor. Educated at the Jesuit college at Nancy, he became curé (priest) of Emberménil in 1782. In 1783 he was crowned by the Academy of Nancy for his Eloge de la poésie, and in 1788 by that of Metz for an Essai sur la régénération physique et morale des Juifs.

He was elected in 1789 by the clergy of the bailliage of Nancy to the Estates-General, where he soon made his name as one of the group of clerical and lay deputies of Jansenist or Gallican sympathies who supported the Revolution. He was one of the first of the clergy to join the third estate, and contributed notably to the union of the three orders; he presided at the session which lasted sixty-two hours while the Bastille was being attacked by the people, and spoke vehemently against the enemies of the nation. He later took a leading role in the abolition of the privileges of the nobles and the Church.