Marjorie Blackwood-Schelling (born 1 May 1957 in Karachi, Pakistan) is a Canadian retired tennis player. Partnering the Australian Susan Leo, she reached the doubles quarter-finals at Wimbledon in 1981 and 1982, and with Pam Whytcross, also Australian, the French Open in 1980. She was the coach/captain of the Canadian Federation Cup team in 1983. She was Tennis Canada's 1982 female player of the year. Born to a Canadian government officer in Karachi, she grew up in Detroit and Ottawa and attended the University of Texas.