Frankfurt am Main commonly known simply as Frankfurt, is the largest city in the German state of Hesse and the fifth-largest city in Germany, with a 2009 population of 672,000. The urban area had an estimated population of 2,295,000 in 2010. The city is at the centre of the larger Frankfurt/Rhine-Main Metropolitan Region which has a population of 5,600,000 and is Germany's second largest metropolitan area.

In English, this city's name translates to "Frankfurt on the Main" (pronounced like English mine or German mein). The city is located on an ancient ford on the river Main, the German word for which is "Furt". A part of early Franconia, the inhabitants were the early Franks. Thus the city's name reveals its legacy as being the "ford of the Franks".

Situated on the Main River, Frankfurt is the financial and transportation centre of Germany and the largest financial centre in continental Europe. It is seat of the European Central Bank, the German Federal Bank, the Frankfurt Stock Exchange and the Frankfurt Trade Fair, as well as several large commercial banks. Frankfurt Airport is one of the world's busiest international airports, Frankfurt Central Station is one of the largest terminal stations in Europe, and the Frankfurter Kreuz (Autobahn interchange) is the most heavily used interchange in continental Europe. Frankfurt is the only German city listed as one of ten Alpha world cities. Frankfurt lies in the former American Occupation Zone of Germany, and it was formerly the headquarters city of the U.S. Army in Germany.

Frankfurt is considered an alpha world city, as listed by the Loughborough University group's 2008 inventory, is ranked 21st among global cities by Foreign Policy's 2008 Global Cities Index and is an international centre for commerce, finance, culture, transport, education, and tourism. According to the Mercer cost of living survey, Frankfurt is Germany's second most expensive city, and the 48th most expensive in the world. Frankfurt also ranks among the top 10 most livable cities in the world according to Mercer Human Resource Consulting.

Among English speakers, the city is commonly known simply as "Frankfurt", though Germans occasionally call it by its full name when it is necessary to distinguish it from the other (significantly smaller) "Frankfurt" in the state of Brandenburg, Frankfurt (Oder).