Donald Trump officially becomes the 45th US president today.
The final preparations for his inauguration are taking place in Washington where he arrived with his wife yesterday.
The main ceremony will take place at the White House and Mr Trump will be sworn in at the Capitol building.
As protesters started gathering, Mr Trump promised huge crowds at a concert at the Lincoln Memorial in Washington that he will make America Great Again.
Thank you for joining us at the Lincoln Memorial tonight- a very special evening! Together, we are going to MAKE AMERICA GREAT AGAIN! pic.twitter.com/5d774OCx5o
— Donald J. Trump (@realDonaldTrump) January 20, 2017
Thousands of protesters took to the streets of New York last night on the eve of the inauguration.
A group of celebrities, including Robert De Niro, Julianne Moore and Mark Ruffalo, were at the rally outside Trump Hotel
Actor Alec Baldwin, known for his impressions of Mr Trump on SNL, addressed the crowd:
Alec Baldwin mocks President-elect Donald Trump during a protest rally in New York pic.twitter.com/SNwV9Fi1dE
— ITV News (@itvnews) January 20, 2017
A demonstration will also take place in Dublin today. The rally, at the Central Bank on Dame Street at 5pm will coincide with a number of other protests taking place in cities around the world.
It's being organised by the Anti-Austerity Alliance - People Before Profit TDs, and a number of other anti-war and anti-racism groups.
AAA-PBP TD Richard Boyd Barrett says there are dangerous times ahead.
