Guillaume-Isidore Baron de Montbel (4 July 1787 – 3 February 1861) was a French politician who was a mayor of Toulouse, a deputy and a minister in the French government during the last year of the Bourbon Restoration. He was an ardent royalist and opposed to the freedom of press. After the July Revolution of 1830 he was tried in absentia and sentenced to civil death. He was later pardoned and returned to France.