Leo William "Red" Nonnenkamp (July 7, 1911 – December 3, 2000) was an outfielder in Major League Baseball who played between 1933 and 1940 for the Pittsburgh Pirates (1933) and Boston Red Sox (1938–1940). Listed at 5 ft 11 in (1.80 m), 165 lb., Nonnenkamp batted and threw left-handed. He was born in St. Louis, Missouri.
In a four-season career, Nonnenkamp was a .262 hitter (69-for-263) with 49 runs and 24 RBI in 155 games, including six doubles, two triples, six stolen bases, and a .347 on-base percentage.
Nonnenkamp died at the age of 89 in Little Rock, Arkansas.