Walter Donald Aloysius Signer (October 12, 1910 – July 23, 1974) was a Major League Baseball pitcher who played for the Chicago Cubs in 1943 and 1945. The 6 ft 0 in (1.83 m), 185 lb (84 kg) right-hander was a native of New York City. Signer is one of many ballplayers who only appeared in the major leagues during World War II. He made his major league debut on September 18, 1943, starting the second game of a doubleheader against the St. Louis Cardinals at Sportsman's Park. Signer and the Cubs were shut out 5–0 by 29-year-old rookie Al Brazle.