Lombardy is an administrative region of Italy that covers 23,844 km2 (9,206 sq mi); it is located in northern Italy and has a population of about 10 million people, constituting more than one-sixth of Italy's population. Lombardy is located between the Alps mountain range and tributaries of the river Po, and includes Milan, its capital, the largest metropolitan area in the country, and among the largest in the EU.

The Metropolitan City of Milan is a metropolitan city in the Lombardy region of Italy. It is the second most populous metropolitan city in the nation after the Metropolitan City of Rome Capital. Its capital is the city of Milan. It replaced the province of Milan and includes the city of Milan and other 132 comuni. It was first created by the reform of local authorities and then established by the Law 56/2014. It has been operative since 1 January 2015.