Dame Julie Onum-Nwariaku was born on 30th July 1942 in Kaduna, Kaduna State and hails from Asaga Ohafia Local Government Council of Abia State. She attended Our Lady`s Primary School in Kaduna between 1948-1950, Ohafia Girls School, Asaga Ohaifa, Abia State from 1951 to 1952 and St Stephen`s Primary School Umuahia where she obtained her first school leaving certificate in 1955. She enrolled at Archdeacon Crowther Memorial Girls School Elelenwa, Portharcourt, Rivers State between 1956 and 1962 and University of Ibadan from 1963 to 1966 where she bagged Higher School Certificate and B.Sc (Hons) Economics respectively.
Dame Nwariaku started her working experience in the public service as an Research Assistant, Economic Development Institute, University of Nigeria Nsukka in 1967. She was Administrative Officer in various Ministries in the defunct East Central States from 1970 to 1980. She rose to the position of Deputy Permanent Secretary Ministry of Finance and Economic Development in Imo State 1981-1982, Ministry of Education Imo State 1982-1983 and Ministry of Community Development and Cooperative Imo State in 1982. She also held the position of Permanent Secretary in Ministries of Economic Development( Cabinet Office), Ministry of Education, Ministry of Commerce and Industry all in Imo State between 1984 and 1988. Between 1988 and 1992, she was Director- General Ministries of Commerce and Industry, Ministry of Finance and Ministry of Finance, Commerce and Industry in Imo and Abia States. Before her appointment as Honourable Member of the ICPC in July 2007, she was Executive Director in Progress Bank of Nigeria from January 1993 to March 1995. Dame Nwariaku was also the Chairperson African Union Advisory Board on Corruption from January 2011 to January 2013. She has served as chairperson and member of various Presidential Committees and task forces and also belong to various professional Associations and clubs.