Campione d'Italia is an Italian comune (municipality) of the Province of Como in the Lombardy region, being an Italian exclave within the Swiss canton of Ticino, separated from the rest of Italy by Lake Lugano and mountains. The enclave is less than 1 km at the shortest point from the rest of Italy, but the hilly terrain requires a journey by road of over 14 km to reach the nearest Italian town, Lanzo d'Intelvi, and over 28 km to reach the city of Como.

In the first century BC the Romans founded the garrison town of Campilonum to protect their territories from Helvetii invasions.

In 777 Toto of Campione, a local Lombard lord, left his inheritance to the archbishopric of Milan. Ownership was transferred to the abbey of Sant’Ambrogio. In 1521 the surrounding area of Ticino was transferred from the ownership of the bishop of Como to Switzerland by Pope Julius II, as thanks for support in the Wars of the Holy League. However, the abbey maintained control over what is now Campione d'Italia and some territory on the western bank of Lake Lugano.