The area surrounding what is now Plainville was first called the Paradise Flats. The name was derived from the fact it is a large and level plain situated at the head of the Paradise Creek, where buffalo, deer and antelope were once so plentiful it was given the name, “Hunters Paradise.”

A fire in October of 1909 destroyed as many as sixteen business buildings and the opera hall in downtown Plainville. The fire destroyed buildings on both sides of Mill Street and one of the few structures left standing were the stone walls of what is now the True Value Hardware store.

Several former Plainville teachers went on to become very important figures. C. E. Rarick, who served as principal, became president in 1933 of Fort Hays State College, the forerunner of Fort Hays State University. Rarick Hall, on the FHSU campus, is named for the former president. Also, Jack Hartman, a football coach at PHS, would go on to become legendary at Kansas State University as a basketball coach and was inducted into the Kansas Sports Hall of Fame. U.S. Senator Jerry Moran grew up in Plainville.

Today, Plainville is home to Dessin Fournir Companies, a worldwide design firm specializing in furniture, cloth, draperies, and lighting.