Küster (German for "sacristan") is a German occupational surname. Notable people with the surname include:
Ernst Küster (1874–1953), German botanist Ernst Georg Ferdinand Küster (1839–1930), German surgeon Heinrich Küster (1870–1956), German architect and town officer Heinrich Carl Küster (1807–1876), German malacologist and entomologist Konrad Küster (born 1959), German musicologist Ludolph Küster (1670–1716), German classical scholar, editor of ancient Greek texts Susen Küster (born 1994), German hammer thrower
See also Mother Küsters' Trip to Heaven, a 1975 German film by Rainer Werner Fassbinder Kuster Kuester