Warren Louis Hacker (November 21, 1924 – May 22, 2002) was an American professional baseball player, a pitcher for the Chicago Cubs (1948–56), Cincinnati Redlegs (1957), Philadelphia Phillies (1957–58) and Chicago White Sox (1961). He was also the uncle of former Major League shortstop Rich Hacker. The native of Marissa, Illinois, died in 2002 in Lenzburg, Illinois, at the age of 77.