[2] The county was named after Matthew Cowley, first lieutenant in Company I, 9th Kansas Cavalry, who died during the American Civil War.

The first European visitor to Kansas was the Spanish explorer Francisco Vasquez de Coronado in 1541.

In 1601, the Governor of New Mexico, Juan de Oñate, visited Etzanoa, a settlement of several thousand Wichita people near Arkansas City along the Walnut River.

In 1870, the county was renamed for Matthew Cowley, First Lieutenant in Company I, 9th Kansas Cavalry, who died at Little Rock, Arkansas, on October 7, 1864.

Finally settled after two special elections and numerous petitions to the Governor and Legislature, Winfield was determined to be the county seat and a courthouse was constructed in 1873 at a cost of $11,500.

[3] In 2010, the Keystone-Cushing Pipeline (Phase II) was constructed north to south through Cowley County.

[8] West of Dexter, KS, Cowley County Fishing Lake is positioned just off of Highway 166.

This fishing lake is the home of the Cowley County Waterfall, which can be visited following the road to the northwest side of the property.

† means a community is designated a Census-Designated Place (CDP) by the United States Census Bureau.

Former head coach and for the Oklahoma Sooners and College Football Hall of Fame member Bennie Owen was born in Arkansas City.

Perhaps the most famous resident of Cowley County is the fictional character Mary Ann Summers from the television show Gilligan's Island.