Margot Lumb was an Englishsquash and tennis player.
As a squash player she won the British Open five times in a row from 1935-39. She won all five finals in straight sets. She was also the runner-up at the championship in 1934, when she lost to Susan Noel.
Lumb also won the United States Hardball National Championship in 1935.
As a tennis player, Lumb participated in the British Wightman Cup team in 1937 and 1938. She was a finalist in the 1937 All England Plate tournament, a tennis competition held at the Wimbledon Championships which consisted of players who were defeated in the first or second rounds of the singles competition. She lost the final in straight sets to Freda James. Lumb was the runner-up at the 1938 German Championships singles event, losing the final in straight sets to defending champion Hilde Sperling.