Campione d'Italia is an Italian comune (municipality) of the Province of Como in the Lombardy region, occupying an enclave 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.

First settlements in the area date back to the first century BC, when the Romans founded the garrison town of Campilonum to protect their territories from Helvetii invasion attempts.

Its status came about when Ticino chose to become part of the Swiss Confederation in 1798, and Campione's people chose to remain part of Lombardy, which subsequently became part of Italy in 1859. An alternative explanation is that, in the year 787, the lands of what is present-day Campione were controlled by a man who ceded this land to the Church of San Ambrogio in Milan as a token of appreciation for the skill of the Milanese craftsmen. The d'Italia was added to the appellation under Prime Minister Benito Mussolini, who was keen to showcase Campione to its neighbours.