Horst-Herzhorn is an Amt (collective municipality) in the district of Steinburg, in Schleswig-Holstein, Germany. The seat of the Amt is in Horst. Before 1 January 2008, when it was merged with the Amt Herzhorn, it was named Amt Horst.
The Amt Horst-Herzhorn consists of the following municipalities:
Coordinates: 53°49′01″N 9°37′01″E / 53.817°N 9.617°E