Which sovereign state is the world's smallest by area?

Vatican City is the world’s smallest sovereign state by area, occupying about 0.49 square kilometres inside Rome, Italy.

It is a landlocked city-state and an enclave surrounded by Italy. Its sovereignty was established through the Lateran Treaty, signed by the Holy See and the Kingdom of Italy in 1929. The arrangement resolved the long-running dispute created when the Papal States lost most of their territory in the 19th century and gave the pope an independent territorial base.

Vatican City is governed by the pope and serves as the administrative centre of the Catholic Church. The sovereign entity behind its diplomacy and international legal relations is the Holy See, a distinction that often causes confusion: the Holy See and Vatican City are closely connected but are not identical. The state is also generally described as the world’s smallest by population. San Marino, Monaco, and Nauru are sovereign microstates, but each has a larger land area.