Mr Menon studied law at the National University of Singapore in 1986 and later obtained a Masters degree from Harvard Law School. He was admitted as an advocate and solicitor of the Supreme Court of Singapore in 1987 and as an Attorney and Counsellor-at-law of the Bar of the State of New York in 1992. He was appointed Senior Counsel in January 2008.As a private practitioner, Mr Menon was recognised as one of the leading lawyers in the fields of commercial litigation and arbitration, insolvency and construction law, in Singapore and abroad. He advised and represented numerous local and overseas clients in complex and technical disputes and appeared before as well as in arbitration tribunals in various jurisdictions.

Mr Menon has also served as the Deputy Chairman of the Singapore International Arbitration Centre and has represented Singapore at the UNCITRAL Working Group on Arbitration.

From April 2006 to March 2007, Mr Menon served as a Judicial Commissioner of the Supreme Court and presided over several prominent criminal and civil cases in the High Court. After completing his term on the Bench, he returned to Rajah & Tann becoming its Managing Partner in August 2009. He was appointed as the Attorney-General of Singapore on 1 October 2010. He stepped down as the Attorney-General on 24 June 2012, was appointed as a Judge of Appeal of the Supreme Court on 1 August 2012 and as the Chief Justice on 6 November 2012.