In just a matter of days Donald Trump will be inaugurated as the 45th President of the United States.
The grand ceremony will take place in Washington DC with 1,600 guests attending - including Barack Obama, Cabinet members, diplomats and the elite of American politics.
Hillary Clinton and her husband - former US President Bill Clinton - will also be present despite the bitter election campaign between Hillary and Trump.
It is a long-standing custom that former leaders and their spouses attend the ceremony.
But what is the inauguration and what does it involve? Here's everything you need to know and how you can watch it.
When and where is it?
The inauguration of Donald Trump - as the 45th President of the United States - will take place on Friday, January 20. It will happen on the West Front of the United States Capitol building in Washington, D.C.
The event will begin at noon (5pm GMT). It will start at the White House and end at a number of Inaugural Balls across the city.
What will happen on the day?
- A prayer: This is a tradition which was started by Franklin D Roosevelt in 1933. Presidents including Obama, Reagan, Truman and Roosevelt all attended theirs at the St John's Episcopal Church, which is across the street from the White House.
- A meeting between Obama and Trump: The departing and incoming Presidents will have a brief meeting at the White House and will then travel together to the Capitol - which is the home of the US Legislation and where the inauguration will take place.
- Vice-President's oath: Vice President-elect Mike Pence will be the first to take the oath of office.
- Trump is sworn in: This is when the President will take his oath and it is considered the most important part of the day. It is likely he will swear on the Bible but in the past some former presidents choose not to. John Quincy Adams and Franklin Pierce took theirs using a book of law whilst Theodore Roosevelt didn't swear on anything.
- The Inaugural Address This is a speech Trump will give during the ceremony which will inform people of his intentions as the leader. It can vary in length from George Washington's 135 words in 1789 to William Henry Harrison's 8,445 words in 1841. After the speech this is traditionally the time the ex-President (in this case Obama) usually makes a swift exist. Bush left by helicopter in 2009 after Obama's Inaugural address.
- The Inaugural Parade After all the formalities are over everyone enjoys an afternoon lunch before the parade starts. 8,000 ceremonial soldiers, floats and marching bands proceed down Pennsylvania Avenue to the White House.
Inaugural Balls There will be a number of black-tie parties and events to celebrate the new President. In1997 there were 14 for Bill Clinton and Barack Obama attended 10 in 2009.
How can I watch?
All major news outlets will be covering events on the day of the inauguration - you will be able to keep update online and on TV news channels.