After graduating from the universities of Auckland and Oxford, Judge Baragwanath began his career at the New Zealand bar and was appointed Queen's Counsel in 1983. He has prosecuted and defended major criminal cases including murder trials and complex fraud proceedings. Judge Baragwanath has sat as a judge of the High Court and the Court of Appeal of New Zealand, where he dealt with civil, criminal and international litigation.
From 1996 to 2001 Judge Baragwanath was president of the New Zealand Law Commission. In 2004 he was appointed chairman of the Rules Committee of the Courts of New Zealand.
From 2007, he was the presiding judge of the Court of Appeal of Samoa, resigning in 2012. He retired from the New Zealand court of appeal in August 2010 where he was a permanent member. In addition to his judicial activities, Judge Baragwanath has lectured widely and presented papers on international and domestic human rights, constitutionality and the rule of law as well as international judicial cooperation.
He has received visiting appointments at Cambridge, Queen Mary London and Hong Kong Universities, and the Netherlands Institute of Advanced Studies. He is an overseas bencher of the Inner Temple in London and was appointed to the Special Tribunal for Lebanon in March 2009. In 2010 Judge Baragwanath was made a knight companion of the New Zealand order of merit, in recognition of his services as a judge of the Court of Appeal of New Zealand.
Judge Baragwanath elected President of the Tribunal on 10 October 2011 and served until 28 February 2015. He succeeded Judge Antonio Cassese.