The Upper Silesian metropolitan area is a polycentric metropolitan area in southern Poland and northeastern Czech Republic, centered on the cities of Katowice and Ostrava, and has around 5 million inhabitants. Geographically, it is located mainly in Upper Silesia, with small parts of the area also in the historical regions of Moravia and Lesser Poland. Administratively, it is located in the three administrative units : mainly Silesian Voivodeship and a small western part of Lesser Poland Voivodeship in Poland, and also a small eastern part of Moravian-Silesian Region in the Czech Republic.

Katowice is the capital city of the Silesian Voivodeship in southern Poland and the central city of the Katowice urban area. As of 2021, Katowice has an official population of 286,960, and a resident population estimate of around 315,000. Katowice is a central part of the Metropolis GZM, with a population of 2.3 million, and a part of a larger Upper Silesian-Moravian metropolitan area that extends into the Czech Republic and has a population of around 5 million people, making it one of the most populous metropolitan areas in the European Union.