The Treaty of Lausanne (French: Traité de Lausanne) was a peace treaty signed in Palais de Rumine,  Lausanne, Switzerland, on 24 July 1923. It officially settled the conflict that had originally existed between the Ottoman Empire and the Allied French Republic, British Empire, Kingdom of Italy, Empire of Japan, Kingdom of Greece, and the Kingdom of Romania since the onset of World War I. The original text of the treaty is in French. It was the result of a second attempt at peace after the failed Treaty of Sèvres, which was signed by all previous parties, except the Kingdom of Greece, but later rejected by the Turkish national movement who fought against the previous terms and significant loss of territory. The Treaty of Lausanne ended the conflict and defined the borders of the modern Turkish Republic. In the treaty, Turkey gave up all claims to the remainder of the Ottoman Empire and in return the Allies recognized Turkish sovereignty within its new borders.
The treaty was ratified by Turkey on 23 August 1923, Greece on 25 August 1923, Italy on 12 March 1924, Japan on 15 May 1924, Great Britain on 16 July 1924. The treaty came into force on 6 August 1924, when the instruments of ratification had been officially deposited in Paris, France.