Hanerau-Hademarschen is a municipality in the district of Rendsburg-Eckernförde, in Schleswig-Holstein, Germany. It is situated near the Kiel Canal, approx. 25 km southwest of Rendsburg.Hanerau-Hademarschen was until 2008 the seat of the Amt ("collective municipality") Hanerau-Hademarschen. Now the seat of the Amt is Hohenwestedt which is outside the area of Hanerau-Hademarschen.