Bret William Walker SC (born 1954) is an Australian barrister, stationed at Fifth Floor St James' Hall Chambers.
Walker was educated at The King's School in Sydney, and graduated with degrees in arts and law from the University of Sydney.
Walker was admitted to the New South Wales bar in 1979. He was appointed Senior Counsel in 1993, and was president of the NSW Bar Association from November 2001 to November 2003, having been vice-president from 1996 to 2001. He was president of the Law Council of Australia from 1997 to 1998.
Walker is a member of the Council of Law Reporting for New South Wales, and has been editor of the NSW Law Reports since 2006. He is a patron of the State Library of NSW as a foundation senior fellow and has been a member of the NSW Health Clinical Ethics Advisory Panel since 2003. He was governor of the Law Foundation of NSW from 1996 to 2007, and Special Commissioner of Inquiry for the NSW government into Sydney Ferries in 2007. He has been a director on the board of the Sydney Writers' Festival since 2000. He was a foundation member and has been director of the Australian Academy of Law since 2007.
Walker is the chairman of The Red Room Company, a not-for-profit organisation that creates, publishes and promotes poetry in unusual ways.
He was one of the leading legal counsel representing tobacco companies in their fight against the Australian government's plain packaging legislation.
In April 2011, Walker was appointed as the Independent National Security Legislation Monitor. In 2015, Walker said that a proposed change to Australia's citizenship laws to give the Minister for Immigration the power to strip citizenship from people who support terrorism was unconstitutional. He said this was a misquote of the INSLM 2014 report by Prime Minister Tony Abbott. In a 2015 interview with Lateline, Walker noted the Australian "habit of seeing a problem and passing a law about it".