Kenneth Leo Retzer (April 30, 1934 – May 17, 2020) was an American professional baseball player. He was a catcher in Major League Baseball for the Washington Senators from 1961 to 1964. Retzer batted left-handed, threw right-handed and was listed as 6 feet (1.8 m) tall and 185 pounds (84 kg). He was born in Wood River, Illinois.
Retzer died at his home in Sun City, Arizona on May 17, 2020 at the age of 86.