Hörnerkirchen is an Amt ("collective municipality") in the district of Pinneberg, in Schleswig-Holstein, Germany. It is situated approximately 12 km northeast of Elmshorn. The seat of the Amt is in Brande-Hörnerkirchen.

The Amt ("collective municipality") Hörnerkirchen consists of the following municipalities (population in 2005 between brackets):

Coordinates: 53°51′N 9°43′E / 53.850°N 9.717°E / 53.850; 9.717