Karl Arnold (1901–1958) was a German politician.
Karl Arnold may also refer to:
Karl Arnold (chemist) (1853–1929), German chemist and mountaineer Karl Arnold (painter) (1883–1953), German painter Karl Arnold (weightlifter) (1940–2012), German Olympic weightlifter
See also Carl Arnold (American football), American football coach Carl Arnold (composer) (1794–1873), German composer