Joseph R. Biden Jr has been sworn in by Supreme Court chief justice John Roberts, becoming the 46th president and the oldest holder of the office.
He uses a five-inch-thick family bible which dates back to 1893 which is held by his wife, Jill.
Mr Biden recites the presidential oath of office: “I do solemnly swear that I will faithfully execute the Office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States.”
Kamala Harris is sworn in by Supreme Court Justice Sonia Sotomayor, becoming America’s first female, first black and first South Asian American vice president.
In his first speech as the 46th president, Biden said: “this is America’s day and democracy’s day”.
He adds: “The will of the people has been heard and the will of the people has been heeded.”
“Democracy has prevailed”.