The Iroquois League was a confederation of six native American nations in the northeastern United States which was formed towards the end of the 16th century.

The League was an novel association of sovereign nations held together by a constitution based on the structure of the confederation and its decision-making apparatus rather than on the power of individuals. This formed much of the basis for the American invention of government and it became the model that the framers of the U.S. Constitution would turn to in designing a nation that was, in theory, a set of sovereign nations: the United States.

During the American Revolution, the League split apart; some siding with the Americans, while others allied themselves with Britain. This led the United States, in 1784, to disband the League.