William Fischer may refer to:
Bill Fischer (Australian footballer) (1883-1917), Australian rules footballer and soldier,
Bill Fischer (American football) (born 1927), American football player,
Bill Fischer (baseball) (born 1930), former American Major League Baseball pitcher,
William Fischer (baseball) (1891-1945), catcher in Major League Baseball,
William S. Fischer, American composer, conductor, arranger, and producer who has worked with Cannonball Adderley and Joe Zawinul, among others
