Ambroise Croizat (28 January 1901 Notre-Dame-de-Briançon (Savoie) – 11 February 1951 in Suresnes) was a French syndicalist and politician.
As the minister of Labour and of Social security, he founded the French Social security system (or social safety net) and the retirement system, between 1945 and 1947.
He was also the general secretary of the Fédération des travailleurs de la métallurgie CGT.