Richterswil (Swiss German: Richtischwiil ) is a municipality in the district of Horgen in the canton of Zürich in Switzerland.

Richterswil is first mentioned in 1265 as Richtliswile.

During the 17th Century, a series of peasant revolts broke out across Switzerland. One of these revolts, the 1645/46 Wädenswiler Steueraufstand (Wädenswil tax revolt), occurred around Lake Zürich and involved the village of Richterswil. The Richterswiler Weibel Rudolf Goldschmid was one of the leaders of the revolt who was executed in Zürich following the failure of the revolt. During the first Villmergen war (1656) Richterswil was invaded by an army from Schwyz.