John D. Powless (born August 24, 1932) is a retired American basketball and tennis coach at the University of Wisconsin–Madison and a current player on the international senior tennis circuit.
Powless was born and raised in Flora, Illinois, and played on the Flora High School basketball, tennis and football teams, where he won the State tournament in tennis his senior year, the only person to have done so below Decatur, a record still holds to this day, 2014. He graduated from Murray State University in 1957 after playing basketball and tennis and still ranks among the school’s all-time greats in both sports. He was one of five charter members in Murray State’s Hall of Fame, which was originated in 1957.
As a 6'5" sophomore forward in 1955, he led his team to the Kentucky Invitational title. As a tennis player, Powless never lost a tennis match in three years of varsity competition and was the Ohio Valley Conference singles champion all three seasons. He also shared the conference doubles championship all three years and later served six years as captain and coach of the United States Junior Davis Cup team. Powless lost in the first round of the 1955, 1956, 1962, and 1963 U.S. National Championships, but reached the second round in 1959 and 1964. He defeated US #1 Barry MacKay in the 1960 Atlanta tournament, and won the event.
After graduation, Powless coached at the high school level at Paducah, Kentucky for a year and joined Bud Kennedy as an assistant basketball coach at Florida State University the following year. In 1960, he became freshman coach at the University of Cincinnati and compiled a 36-9 three-year record and a 15–0 record during the 1962–63 season. Working with head coach Ed Jucker and assistant (and later head) coach Tay Baker, Powless helped the Bearcats post a 78–6 record over three years. During the three years that Powless was at Cincinnati, the Bearcats won two NCAA titles by defeating Ohio State in 1961 and 1962 and finished second to Loyola University Chicago in 1963.