The Battle of Vistula Lagoon ( or ) was fought on September 15, 1463 between the navy of the Teutonic Order, and the navy of the Prussian Confederation which was allied with the King of Poland, as part of the Thirteen Years' War (1454–66). The battle was the largest naval battle of the war, and one of the two battles (along with Battle of Świecino) which decided the final outcome of the war.