William Frisbie Watrous (August 10, 1825 – July 18, 1910) was an American fruit farmer and pioneer of Wisconsin and Colorado.

[1] In 1849, he moved west with his wife and infant daughter and settled in the heavily forested Calumet County, Wisconsin, following after his older brother Orrin J. Watrous.

There, he constructed a cabin on his land and worked for years to clear trees to make space for a productive farm, where he took particular interest in growing fruit in the northern climate.

[2] In 1864, he sold his land in Calumet County and moved to the town of Manitowoc, Wisconsin, where he expanded his fruit growing plans.

[3] The Watrous family were descendants of Jacob Waterhouse, who emigrated from England to the Massachusetts Bay Colony sometime before 1637.