Lahn may refer to:

• the Lahn, a river in western Germany
• Lahn, Hesse, a city that existed between 1977 and 1979 as a merger of Wetzlar and Gießen, in Hesse, Germany
• Lahn, Lower Saxony, a municipality in the district of Emsland, Lower Saxony
• Lahn (Wald im Pinzgau), a village in the municipality Wald im Pinzgau, Austria
• Lähn, German name of the town Wleń in Poland

This disambiguation page lists articles about distinct geographical locations with the same name.
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