Kieffer is a surname. Notable people with the surname include:
Aldine Silliman Kieffer (1840–1904), American music writer
Charles Kieffer, American athlete
Eduardo Gudiño Kieffer (1935–2002), Argentine writer
Guy-André Kieffer, French-Canadian journalist
Jean-Jacques Kieffer, French entomologist
Oliver Kieffer (born 1979), French volleyball player
Philippe Kieffer (1899–1962), French naval officer
Susan Kieffer (born 1942), American geologist
