Vice President of the United States,

Biden became the 47th Vice President of the United States on January 20, 2009, when he was inaugurated alongside President Barack Obama. He succeeded Dick Cheney. Biden is the first United States Vice President from Delaware and the first Roman Catholic to attain that office. Biden's oath of office was administered by Supreme Court Justice John Paul Stevens.

As Biden headed to Delaware's Return Day tradition following the November 2008 election, and the transition process to an Obama administration began, Biden said he was in daily meetings with Obama and that McCain was still his friend. The U.S. Secret Service codename given to Biden is "Celtic", referencing his Irish roots.

Biden chose veteran Democratic lawyer and aide Ron Klain to be his vice-presidential chief of staff, and Time Washington bureau chief Jay Carney to be his director of communications. Biden intended to eliminate some of the explicit roles assumed by the vice presidency of Cheney. But otherwise, Biden said he would not model his vice presidency on any of the ones before him, but instead would seek to provide advice and counsel on every critical decision Obama would make. Biden said he had been closely involved in all the cabinet appointments that were made during the transition. Biden was also named to head the new White House Task Force on Working Families, an initiative aimed at improving the economic well-being of the middle class.

As his last act as Chairman of the Foreign Relations Committee, Biden went on a trip to Iraq, Afghanistan and Pakistan during the second week of January 2009, meeting with the leadership of those countries.