Petronella ("Petra") Grietje van Staveren (born 2 June 1966) is a former breaststroke swimmer from the Netherlands who won the gold medal in the 100 meter breaststroke at the 1984 Summer Olympics in Los Angeles. She also won a bronze at the 1986 world championships and a European silver in 1983 in the 4×100 meter medley relay. She finished five times in fourth place at European championships in 1981–1985.