His father, the son of Victorian premier Charles Gavan Duffy, served as Chief Justice of Australia from 1931 to 1935.
[1] Duffy served his articles of clerkship in Wangaratta and was admitted to the Victorian Bar in 1908, joining the chambers of his cousin's husband Hayden Starke.
According to the Australian Dictionary of Biography, he "proved a competent judge, gifted with keen memory and complete independence of mind and conducting his court admirably".
In 1952, Duffy was appointed as one of three royal commissioners into allegations of bribery made to state MPs, along with the chief justice Edmund Herring and judicial colleague Russell Martin.
[5] Duffy married Mary Marjorie Alexa Back in 1919; the couple had twin sons who died at birth.