Brest-Litovsk, Treaty of, in World War I, the peace treaty that Germany and its allies forced Russia to sign on March 3, 1918. After the Russian Revolution of 1917 the Bolsheviks agreed to an armistice. Peace negotiations were opened at Brest-Litovsk (now Brest, Belarus), but Russia refused to accept the German terms.

Germany then recognized the independence of Ukraine and made a peace treaty with it. The German armies reopened the war, and soon Russia had to accept demands even worse than the earlier terms. Russia recognized the independence of Ukraine; surrendered Poland, Lithuania, Latvia, Estonia, and Finland; and ceded Kars, Ardahan, and Batum to Turkey. But the treaty was short-lived. After the Armistice of November 11, 1918, the Allies forced Germany to renounce the Treaty of Brest-Litovsk.