Horgen District is a district of Canton of Zürich in Switzerland.

The district is located in the Zimmerberg and Sihl Valley region on the left shore of Lake Zürich; its district capital is Horgen.

The district consists of 11 municipalities and has a population of 127,263 (as of 31 December 2020) and an area of 104.16 km2 (40.22 sq mi).