Reginald Ian Barrett AO (born 1 April 1944) was a Judge (2001–2015) and Judge of Appeal (2012–2015) of the Supreme Court of New South Wales and became an acting Judge of Appeal in 2016.
He had been a corporate and securities lawyer and a partner in Mallesons Stephen Jaques, general counsel for Westpac Banking Corporation and 20 year partner with Allen Allen & Hemsley.