The Rhine-Main Metropolitan Region, often simply referred to as Frankfurt Rhine-Main, Frankfurt Rhine-Main area, or Rhine-Main area is the second-largest metropolitan region in Germany after Rhine-Ruhr, with a total population exceeding 5.8 million. The metropolitan region is located in the central-western part of Germany, and stretches over parts of three German states: Hesse, Rhineland-Palatinate, and Bavaria. The largest cities in the region are Frankfurt am Main, Wiesbaden, Mainz, Darmstadt, Offenbach, Worms, Hanau, and Aschaffenburg.
The polycentric region is named after its core city, Frankfurt, and the two rivers Rhine and Main. The Frankfurt Rhine-Main area is officially designated as a European Metropolitan region by the German Federal Ministry of Transport, Building and Urban Affairs and covers an area of roughly 13,000 square kilometers.