The Convention of Klosterzeven (or the Convention of Kloster-Zeven, ) was a convention signed on 10 September 1757 at Klosterzeven between France and the Electorate of Hanover during the Seven Years' War that led to Hanover's withdrawal from the war and partial occupation by French forces. It came in the wake of the Battle of Hastenbeck on 26 July in which Hanover had suffered a devastating defeat. Following the battle the Army of Observation had retreated northwards until it had reached Stade.