Denise O’Brien was born in Brisbane in July 1937 where she became a skilled fencer. O’Brien competed in the individual foil event at the 1956 Melbourne Olympics but finished last in her pool. Whilst at the Melbourne Games she met her future husband Ed Wild, who was part of the Canadian basketball team. The couple married in December 1958 and raised a family of five children in Vancouver. Earlier in 1958 O’Brien also represented Australia at the British Empire and Commonwealth Games in Cardiff, Wales.