The Lateran Treaty was one component of the Lateran Pacts of 1929, agreements between the Kingdom of Italy under King Victor Emmanuel III and the Holy See under Pope Pius XI to settle the long-standing Roman Question. The treaty and associated pacts were named after the Lateran Palace where they were signed on 11 February 1929, and the Italian parliament ratified them on 7 June 1929. The treaty recognised Vatican City as an independent state under the sovereignty of the Holy See. The Italian government also agreed to give the Roman Catholic Church financial compensation for the loss of the Papal States. In 1948, the Lateran Treaty was recognized in the Constitution of Italy as regulating the relations between the state and the Catholic Church. The treaty was significantly revised in 1984, ending the status of Catholicism as the sole state religion.

The Roman question was a dispute regarding the temporal power of the popes as rulers of a civil territory in the context of the Italian Risorgimento. It ended with the Lateran Pacts between King Victor Emmanuel III of Italy and Pope Pius XI in 1929.