Martin-Michel-Charles Gaudin, 1st Duc de Gaete (19 January 1756 – 5 November 1841) was a French statesman, Napoleon I Bonaparte's Minister of Finances from November 1799 to March 1814, including the Cent Jours following Napoleon's return from Elba.
After Napoleon made him his Minister of Finance, where he held office until 1814, Gaudin organised the French direct contributions, reintroduced direct taxes ("droits réunis"), founded the Banque de France and the Cour des comptes, and set up the first cadaster, or record of land ownership as a basis of taxation. He was rewarded in 1809 with the duché grand-fief of Gaeta, in the then-French controlled kingdom of Naples; effectively, this was a life peerage, nominal but of high rank. During his Cent Jours return, Bonaparte reserved a seat for Gaudin in the planned imperial Chamber of Peers, but that never materialised.
After the Bourbon restoration, he was deputy for the Aisne département, sitting with the constitutional party.
In 1820 he became governor of the Banque de France.
He died in the Gennevilliers chateau, near Paris, in 1841. He left his Memoirs, Opinions and Writings.