Lichtenau is a small town in Rastatt district in southwestern Baden-Württemberg, Germany.

The city shares borders with the following communities, listed clockwise from the north: Rheinmünster, Ottersweier, Achern and Rheinau.

Lichtenau developed from a water castle that the Bishop of Strasbourg had built in the years 1293 to 1296, complete with defensive wall, ditch and parapet.

In 1300 Lichtenau received its city charter and until its Slighting in 1686 it remained a fortress.

The city is part of the administrative district of "Rheinmünster-Lichtenau" with seat in Rheinmünster.