Paul Brereton was educated at Knox Grammar School and the University of Sydney, admitted as a solicitor in New South Wales in 1982, called to the Bar in 1987 and appointed Senior Counsel in 1998. At the Bar, he had a diverse general practice.
In 2005, he was appointed a Judge of the Supreme Court of New South Wales, where he was assigned primarily to the Equity Division, and was the Corporations List Judge and Adoptions List Judge. He was also the judge supervising the Costs Assessment Scheme on behalf of the Chief Justice. From 2013 he was also a member of the Defence Force Discipline Appeal Tribunal and from 2019 Deputy President of the Tribunal.
On 23 August 2018, he was appointed a Judge of Appeal.
He retired from his judicial appointments on 31 May 2023, in order to assume the appointment of inaugural Commissioner of the new National Anti-Corruption Commission from 1 July 2023. He remains Deputy Chairperson of the NSW Law Reform Commission, to which he was appointed in 2016.
He is one of the four authors of the current (tenth, 2019) edition of Nygh’s Conflict of Laws in Australia.
He enlisted in the Army Reserve in Sydney University Regiment in 1975, and was commissioned in the Royal Australian Infantry in 1979. He has served as Second in-command Sydney University Regiment (1994-6), Commanding Officer 4th/3rd Battalion, the Royal New South Wales Regiment (1997-99), Chief of Staff 5th Brigade (2004-5), Assistant Chief of Staff Land Headquarters (2006-7), and Commander 5th Brigade (2008-10). He was promoted Major General in December 2010 on appointment as Head of Reserves & Cadets (2011-2013). In 2016-2020, as an Assistant Inspector-General of the Australian Defence Force he led the IGADF Afghanistan Inquiry into alleged war crimes in Afghanistan. He currently holds honorary appointments as Colonel Commandant of the Royal New South Wales Regiment and the University of New South Wales Regiment.
He was appointed a Member of the Order of Australia in the Military Division in 2010 for exceptional service as Chief of Staff 5th Brigade, Assistant Chief of Staff Land Headquarters and Commander 5th Brigade.