Bärbel Köster (later Madaus, born 26 May 1957) is an East German canoe sprinter who competed in the mid to late 1970s. She won a bronze medal in the K-2 500 m event at the 1976 Summer Olympics in Montreal.
Köster also won four gold medals at the ICF Canoe Sprint World Championships with two in the K-2 500 m event (both 1974 and 1975) and two in the K-4 500 m event (both 1974 and 1975).