Marjolijn Both (born 9 September 1971 in Amsterdam, Netherlands) is a former synchronized swimmer from the Netherlands. She competed in both the women's solo and the women's duet competitions at the 1992 Summer Olympics in Barcelona.
Both trained with the club Zwemvereniging De Dolfijn. She won a bronze medal in the women's duet event at the 1991 European Aquatics Championships in Athens, representing the Netherlands. She stands 170 cm (5 ft 7 in) tall and competed at a weight of 57 kg (126 lb).
