Sergei Borisovich Ivanov (born 31 January 1953) is a Russian senior official and statesman. He was Minister of Defence from March 2001 to February 2007, Deputy Prime Minister from November 2005 to February 2007, and the First Deputy Prime Minister from February 2007 to May 2008. Previously, as secretary of the Russian Security Council, Ivanov served as an adviser to President Boris Yeltsin and later President Vladimir Putin (November 1999-March 2001) on matters of national security. After the election of Dmitry Medvedev as President of Russia, Ivanov was reappointed a deputy prime minister in Vladimir Putin's second government. In December 2011 he was appointed Chief of Staff Presidential Administration of Russia.