The 1917 Franco-Russian agreement was a secret treaty between the French Third Republic and the Russian Empire to support one another's territorial claims in settlement following the First World War. Under the agreement France recognised Russia's claim to any portions of Poland that she could occupy, and Russia supported France's claim for the return of Alsace–Lorraine from Germany and right to occupy other parts of Germany in the post-war period.
Formal acceptance letters between the two parties were exchanged on 10 March but the treaty had little effect as the Russian government fell days later during the February Revolution. The French government of Aristide Briand fell on 20 March, and representatives of the replacement Alexandre Ribot administration agreed with the new Russian Provisional Government that the treaty had been a mistake.