Wädenswil (locally often called Wättischwiil, Wädischwiil or Wädi) is a municipality located in the district of Horgen in the canton of Zürich in Switzerland. The population, as of 2013, was about 21,000. On 1 January 2019 the former municipalities of Hütten and Schönenberg were merged into the municipality of Wädenswil.

Before the 2019 merger, Wädenswil had an area of 17.4 km2 (6.7 sq mi). Of this area, 59.3% is used for agricultural purposes, 9.6% is forested, 29.8% is settled (buildings or roads), and the remainder (1.3%) is non-productive (rivers, glaciers or mountains). In 1996 housing and buildings made up 20.8% of the total area, while transportation infrastructure made up the rest (9%).