The Prussian Confederation (German: Preußischer Bund, Polish: Związek Pruski) is an organization formed in 1440 by a group of 53 gentry and clergy and 19 cities in Prussia to oppose the monastic state of the Teutonic Knights.

It is based on the basis of an earlier similar organization, the Lizard Union.

In 1454, the leader of the Confederation, Johannes von Baysen (Jan Bażyński), formally asks the King of Poland, Casimir IV Jagiellon, to incorporate Prussia into the Kingdom of Poland.

This marks the beginning of the Thirteen Years' War between the Teutonic Knights and Poland, with the Prussian cities financing the military costs of the latter.