The Treaty of Hanover was a treaty of defensive alliance signed on 3 September 1725 by the Kingdom of Great Britain, the Electorate of Hanover, the Kingdom of France and the Kingdom of Prussia, an extension of the earlier Anglo-French Alliance. The alliance was formed as a reaction to Austria withdrawing from the Quadruple Alliance and founding the Austro-Spanish alliance at the Peace of Vienna months earlier in May 1725.
The United Provinces and the Kingdom of Sweden later acceded to the Hanoverian Alliance through the Treaties of The Hague (1726) and Stockholm (1727). The Kingdom of Denmark-Norway did not formally join the Hanoverian Alliance but signed the Treaty of Copenhagen with Great Britain and France in April 1727.