Helen Knox (nee Upton) became a barrister after having worked as a journalist for more than two decades. She was educated by the Sisters of Mercy, Boorowa, in south-western New South Wales before winning a bursary to attend Our Lady of Mercy College in Goulburn. In 1927, she was enrolled in the Teachers' College in the grounds of the University of Sydney; by 1931 she had graduated with an Arts degree. In 1937 Knox was appointed to a position on the staff of the 'Sun' newspaper in Sydney; she remained with the paper throughout the Second World War. Returning to the University in 1944, she undertook a Bachelor of Laws degree and graduated in 1950. By now she was writing for Consolidated Press. Knox was admitted to the New South Wales Bar on 12 February 1960 and for a time shared chambers with Cecily Backhouse (later QC and judge of the NSW District Court). Her practice was chiefly in divorce.

Sources used to compile this entry: Brodsky, Juliette, 'Cecily Backhouse Interview, Cecily Backhouse QC interview with Juliette Brodsky, 4 July 2010', in Pioneering Women at the NSW Bar: 1921-1975, New South Wales Bar Association, 2011, http://www.nswbar.asn.au/the-bar-association/pioneering-women#/12_cecily_backhouse; Calendar of the University of Sydney for the Year 1932, Sydney: Angus and Robertson, Ltd., Publishers to the University, 1932, pp. 638, 816; The University of Sydney Calendar Supplement for the Years 1943-1944, Sydney: Alfred Henry Pettifer, Acting Government Printer, Publisher to the University, 1944, p. 5; 1952, p. 378; 'Barristers Admitted', SMH Archives, 13 February 1960, p. 11; New South Wales Law Almanac for 1961, V. C. N. Blight, Government Printer, 1961, pp. 82, 87; pp. 90, 97; 1967, pp. 89, 97; 1977, pp. 62, 79; The Ryerson Index (See: 'Knox, Helen Mary', The Sydney Morning Herald, Saturday 8 August 1987, p. 160).