Klopfer is a German occupational surname, derived from the Middle High German klopfen, meaning "to pound, bang, or hammer", and thus indicating a person in the clothing trade, mining or metal working. The name may refer to:
Bruno Klopfer (1900–1971), German psychologistDonald S. Klopfer (1902–1986), American businessmanEric Klopfer (born 1970), American educatorEugen Klöpfer (1886–1950), German actorGerhard Klopfer (1905–1987), German Nazi officialGoetz Klopfer (born 1942), American race walkerHeini Klopfer (1918–1968), German architectRegina Klopfer (1903–1991), Hungarian singerSonya Klopfer (born 1934), American figure skater