The 43rd President of the United States has just arrived at the Capitol in Washington DC with the President-elect, Barack Obama.
George W Bush will leave office just before noon (5pm GMT).
An estimated two million people are on the National Mall to witness the swearing-in of the first African-American President.
President-elect Obama, Vice President-elect Joe Biden and President Bush and Vice President Cheney had coffee at the White House before making their way to the Capitol.
George W Bush leaves office today with some of the lowest approval ratings on record. Just after the September 11th attacks his rating stood at 90%, As he leaves office it is 22%.
Controversial preacher Rick Warren will give an invocation at the ceremony. Gay rights groups opposed his presence – he has opposed gay marriage and compared homosexuality to incest.
Aretha Franklin will sing before Vice President-elect Joe Biden is sworn in.
At noon President-elect Obama will take the oath of office on the same Bible used by President Abraham Lincoln in 1861.
He will then address the crowd and hundreds of millions on television.