Joe Biden supporters can be heard cheering in New York as news networks begin calling the election in his favour.
A video taken from a skyscraper shows people whooping and cheering, while others appear to be ringing bells to mark the historic moment.
The Democrat went over the magic 270 electoral college votes as Pennsylvania was called in his favour just moments ago.
Mr Biden won 55% of the vote in New York and will now be the 46th President of the United States.
The news came that the former Vice President had defeated Donald Trump as vote counting rolled into a fifth day.
In the end, Biden's route to victory was by flipping back the 'rust belt' industrial states of Wisconsin, Michigan and Pennsylvania which Trump won by slim margins in 2016.
It means his running mate, Kamala Harris will be both the first woman and person of colour to be elected Vice President.
The race was called following the release of 3,000 counted votes from the Commonwealth of Pennsylvania shortly after 4pm UK time, which pushed Biden's lead in the state above 30,000 votes.
President Trump was playing golf on his Virginia golf course when the news broke.
As the likelihood of defeat began to emerge, the President angrily cast doubt on the integrity of the election, attempting to undermine faith in American Democracy.
President Trump has vowed a fight to overturn the result in the courts.
In a rambling statement from the White House late on Thursday night, the President claimed he would "easily win" if only the "legal votes" were counted.
He blamed his plummeting poll leads on postal vote "fraud" and dishonest counting practices, making repeated claims of irregularity in various states without showing any evidence.
