During the 1950s and 1960s Mildred Durne had a successful career as a foil fencer and represented the London Fencing Club and Salle Pearson. Durne made her début for the British team when she competed at the 1957 World Fencing Championships in Paris. She won gold at the European Championships in both 1958 and 1959, in addition to producing consistent results at national and regional competitions from 1955 until 1971. Her favourite event was the Ashton Tournament, which she won on five occasions. Durne was selected to represent Great Britain in the team foil event at the 1964 Tokyo Olympics but she did not compete. Eight years later at the Montréal Games she also captained the British women’s team. Following her fencing career she worked at the Bank of Australia in international travel.