Penelope May Marshall (born 27 July 1989) is a New Zealand swimmer. She won the silver medal in the 4 ÃÂ 200 m freestyle relay at the 2010 Commonwealth Games alongside Lauren Boyle, Amaka Gessler and Natasha Hind. She won the bronze medal with the same team in the 4 ÃÂ 100 m freestyle relay at the same Games. She competed for New Zealand at the 2012 Summer Olympics in the women's freestyle relay.