Diana MacManus (born April 10, 1986) is a female backstroke swimmer from the United States. As a member of the USA National team she competed at the 2001 Goodwill Games held in Brisbane, Australia where she won two silver medals. At the 2002 Short Course World Championships in Moscow, Russia where she brought home two more bronze medals. At the Brazil meet of 2001–2002 FINA Swimming World Cup, she won both the 50 and 100 backstrokes.