Leimen (German pronunciation:[ˈlaɪmən]; Palatine German: Lome) is a town in north-west Baden-Württemberg, Germany. It is about seven kilometres (4+1⁄2 miles) south of Heidelberg and the fourth largest town of the Rhein-Neckar district after Weinheim, Sinsheim and Wiesloch. It directly borders the Heidelberg district of Rohrbach. Leimen is also the area's industrial centre.

Leimen is located on the Bergstraße (Mountain Road) and on the Bertha Benz Memorial Route.

In the context of a communal reform in the 1970s, Leimen was newly created from the villages Leimen, Gauangelloch and Sankt Ilgen. In 1981, the state government of Baden-Württemberg granted Leimen the privilege to be called "town." When Leimen's population exceeded 20,000 in 1990, the city council applied for elevation to a Große Kreisstadt which was granted by the state government on 1 April 1992.