The Zimmerbergbus is a bus network in the Horgen District in Switzerland, operated by the Sihltal Zürich Uetliberg Bahn (SZU) and its local partner firms: AHW Busbetriebe AG in Horgen, Busbetriebe Bamert GmbH in Wollerau, Leuthold Transfer AG in Horgen, and PostAuto Schweiz AG Region Zürich. The network is named after the Zimmerberg.