Isaac René Guy Le Chapelier, also known as Jean Le Chapelier (June 12, 1754 – April 22, 1794) was a French jurist and politician of the Revolutionary period.

He was born at Rennes in Brittany, where his father was bâtonnier of the corporation of lawyers, a title equivalent to President of the Bar. He entered the law profession, and was a noted orator.

In 1789 he was elected as a deputy to the Estates General by the Third Estate of the sénéchaussée of Rennes. He adopted radical opinions, and was one of the founders of the Jacobin Club (or Breton Club), and his influence in the National Constituent Assembly was considerable. On August 3, 1789, he was elected its president for a short term of 2 weeks.

Before the establishment of the constitutional monarchy in France in September of 1791 (see: French Constitution of 1791), Le Chapelier introduced a motion in the National Assembly which prohibited guilds, trade unions, and compagnonnage (as well as the right to strike). Le Chapelier and other Jacobins interpreted demands by Paris workers for higher wages as contrary to the new principles of the Revolution. The measure was enacted law on June 14, 1791 (subsequently known as the Le Chapelier Law) and effectively barred guilds and trade unions in France until 1864.

During the Reign of Terror, as a suspect for having had links with the Feuillants, he temporarily emigrated to Great Britain, but returned to France in 1794, in a hopeless effort to prevent the confiscation of his assets. He was arrested, and guillotined in Paris on the same day as Guillaume-Chrétien de Lamoignon de Malesherbes.

*Lucien Jaume, "Le citoyen sans les corps intermédiaires: discours de Le Chapelier", in Cahiers du Cevipof, Nr. 39, April 2005, pp. 30–40