Siefert is a surname. Notable people with the surname include:
Annemarie Gethmann-Siefert (born 1945), professor of philosophy at the University of Hagen, Germany Janet Siefert, origin of life researcher Louisa Siefert (1845–1877), French poet Paul Siefert, (1586–1666), German composer and organist Silvia Siefert (born 1953), former East German Olympic handball medalist
See also Seifert Seyfert (disambiguation)