The Treaties of Tilsit were two agreements signed by Napoleon I of France in the town of Tilsit in July, 1807 in the aftermath of his victory at Friedland. The first was signed on 7 July, between Tsar Alexander I of Russia and Napoleon I of France, when they met on a raft in the middle of the Neman River. The second was signed with Prussia on 9 July. The treaties ended the War of the Fourth Coalition at the expense of the Prussian king, who had already agreed to a truce on 25 June after the Grande Armée had pursued him to the easternmost frontier of his realm, and in Tilsit ceded about half of his pre-war territories. From those territories, Napoleon had created French client states which were formalized and recognized at Tilsit: the Kingdom of Westphalia, the Duchy of Warsaw and the Free City of Danzig; the other ceded territories were awarded to further French clients and to Russia.

Napoleon not only cemented his control of Central Europe, but also had Russia and the truncated Prussia ally with him against his two remaining enemies, Great Britain and Sweden, triggering the Anglo-Russian and Finnish War. Tilsit also freed French forces for the Peninsular War. Central Europe became a battlefield again in 1809, when Austria and Great Britain engaged France in the War of the Fifth Coalition.