Former Minister of State for Trade and Investment joins the Museum's Board of Trustees.
Lord Green of Hurstpierpoint was appointed as a Trustee by the Prime Minister for a period of four years from 1 April 2014.
The Board of Trustees met yesterday and elected Lord Green its Chair for a term of four years with immediate effect.
Stephen Green is a member of the House of Lords and was Minister of State for Trade and Investment jointly at the Foreign and Commonwealth Office and the Department for Business, Innovation and Skills from 2011-2013.
Prior to his Government role he was Group Chairman of HSBC.
'I am honoured and delighted to take on this role at a world-class British institution which does so much to advance the science of our planet and to inspire young people to want to learn more about all its marvellous complexity,' said Lord Green.
'Lord Green joins us at a time of extraordinary opportunity,' said Museum Director Dr Michael Dixon.
'His breadth of experience and knowledge across Government and business will help us to capitalise on the unique value of our collections and scientific expertise while also taking important steps to increase our self-generated income.'
Lord Green became a life peer in November 2010, as the Baron Green of Hurstpierpoint. He is a former Trustee of the British Museum.