Mannheim is a city in Germany. With 311,342 inhabitants it is the second-largest city in the state of Baden-Württemberg after the capital Stuttgart.

Mannheim is situated at the confluence of the rivers Rhine and Neckar, in the northwestern corner of the state of Baden-Württemberg. The Rhine separates Mannheim from the adjacent Rhineland-Palatinate city of Ludwigshafen. The Hessian border is north of the city. Mannheim is the largest city of the Rhine Neckar Area, a metropolitan area with 2.4 million inhabitants.

Mannheim is unusual among German cities in that its central area is laid out in a grid pattern (called Quadrate, squares), much like many North American cities. Accordingly, its nickname is Quadratestadt (German: for "town of the squares"). The main route through the squares leads to an enormous 18th-century palace. This former seat of the Electors of the Palatinate now houses the University of Mannheim.

Mannheim's city symbol is der Wasserturm (the water-tower), located in the east of the city centre. Mannheim is start and finish of Bertha Benz Memorial Route.

United States military installations
A number of United States military installations are present in Mannheim. The following installations make up the U.S. Army Garrison Mannheim:

• Benjamin Franklin Village (Mannheim-Käfertal) Also home to the Mannheim American High School and Middle School.
• Coleman Barracks/Coleman Army Airfield (Mannheim-Schönau) (American Forces Network-Europe HQ, U.S. Army Confinement Facility Europe) Also home to the 28th Transportation Battalion
• Funari Barracks (Mannheim-Käfertal)
• Spinelli Barracks (Mannheim-Feudenheim)
• Sullivan Barracks (Mannheim-Käfertal) (7th Signal Brigade headquarters) (Headquarters of 504th Signal Battalion, 1961 - 1965)
• Taylor Barracks (Mannheim-Vogelstang) (2nd Signal Brigade headquarters)

The following installations are part of the U.S. Army Garrison Heidelberg but are within the area of the city of Mannheim:

• Friedrichsfeld Service Center (Mannheim-Friedrichsfeld)
• Hammonds Barracks (Mannheim-Seckenheim)
• Stem Kaserne (Mannheim-Seckenheim)

The long-term future of the Mannheim military community is in doubt since it was not included in U.S. Army Europe's 2004 announcement of those military communities that would remain after a long-term restructuring and downsizing of U.S. forces in Europe. The U.S. Army has already closed installations in Mannheim such as the Rhine River Patrol compound in Sandhofen (1958), Gendarmerie Kaserne in Schönau, the NATO bunker in Feudenheim and Turley Barracks in Wohlgelegen.