William Joseph Klem, born William Joseph Klimm (February 22, 1874 – September 16, 1951), known as the "Old Arbitrator" and the "father of baseball umpires", was a National League (NL) umpire in Major League Baseball from 1905 to 1941. He worked 18 World Series, which is a major league record. Klem was posthumously inducted into the Baseball Hall of Fame in 1953.
