More than 100 million viewers in the US alone are expected to watch tonight's debate
Donald Trump and Hillary Clinton go head-to-head in the first televised debate of the US presidential race tonight.
The Republican and Democratic candidates will be trying to gain support from undecided voters ahead of November's election.
Tonight's debate is expected to pull in over 100 million viewers in the US alone, as well as millions of international viewers.
Lester Holt of NBC Nightly News will moderate the debate, which will last 90 minutes. It is being held at Hofstra University in Hempstead, New York.
It will get underway at 2am Irish time.
The Commission on Presidential Debates is advising that fact-checking statements is not the job of the moderator, and that the candidates should fact-check each other.
Last week the Clinton campaign released a list of what it described as the "most discredited lies" from the the Trump campaign, adding that "repeating these false claims would make it impossible for him to get a passing grade in Monday’s critical test before the voters".
Mr Trump, meanwhile, suggested he would consider inviting Gennifer Flowers (who had a sexual encounter with Bill Clinton in the 1980s) to the debate - in response to the Clinton's campaign decision to invite billionaire and Trump critic Mark Cuban to sit in the front row.
However, the Trump campaign - including Trump's running mate Mike Pence - has since indicated that Ms Flowers has not been invited.
If dopey Mark Cuban of failed Benefactor fame wants to sit in the front row, perhaps I will put Gennifer Flowers right alongside of him!— Donald J. Trump (@realDonaldTrump) September 24, 2016
The debate tonight will focus on three broad topics: 'America's Direction', 'Achieving Prosperity', and 'Securing America'.
Further debates between the two candidates are scheduled for the 9th and 19th of October.