Willemijn Margaretha Duyster (born April 5, 1970 in Amsterdam, Noord-Holland) is a former Dutch field hockey defender, who played 87 international matches for the Dutch national team, in which she scored no goals. A player from HGC in the 1990s, she competed at the 1996 Summer Olympics, winning the bronze medal under the guidance of coach Tom van 't Hek. At the same Olympic tournament inAtlanta, Georgia her brother Jeroen won the gold medal with the men's rowing eights.