Stanley township was first settled in 1867 before being organized on in March, 1877. The township bears the same name as a city in Wisconsin, several villages and post offices across the country, and a county in South Dakota.

The township was originally known as Delaven, but after the Board of County Commissioners deferred organization action for several years and the state rejected the original name, the name was changed to Stanley.

The first permanent white settler in Lyon county settled in Stanley. T. W. Castor and his family moved to the township in 1867. Settlers in the township’s early days were largely Scottish.

Swan lake sits on the east side of section 12 of Stanley, and the Redwood River crosses the northern half of the township.