The debate is set to kick off at around 2am UK time, with many keen to stay up late and watch what is sure to be an explosive encounter between the Democratic and Republican candidates.
The main concern of course, is the ever-present threat of yet more controversial comments by Trump, as viewers are keen to see if he will step up to become more presidential or just reduce the whole show into a series of insults.
Well, to get you in the mood for tonight’s debate, here are five of the most controversial things ever said by Donald Trump.
“You know, it really doesn’t matter what the media write as long as you’ve got a young, and beautiful, piece of ass.”
On that notorious wall plan
“I will build a great wall - and nobody builds walls better than me, believe me - and I’ll build them very inexpensively. I will build a great, great wall on our southern border, and I will make Mexico pay for that wall. Mark my words.”
On John McCain
“He’s not a war hero. He was a war hero because he was captured. I like people who weren’t captured.”
On his own daughter
“I’ve said if Ivanka weren’t my daughter, perhaps I’d be dating her.”
On Princess Diana
“I only have one regret in the women department - that I never had the opportunity to court Lady Diana Spencer. I met her on a number of occasions.”