The next most likely predictions are that he will talk first about job creation (odds of 9/4) or Islamic terrorism (10/3).
"The presidential election was a tumultuous one, to say the least, but the drama hasn't stopped there," said Naomi Totten, spokesperson for Betfair, in a press release.
"Trump's inauguration speech is likely to throw out a number of surprises but punters are predicting that the first thing he will address is to 'Make America Great Again.'"
Less likely predictions are that he will first mention fake news (odds currently at 20/1), U.K. politician Nigel Farage (25/1) or the actress Meryl Streep (50/1).
Paddy Power is also taking bets on what Trump will say first in his inauguration speech, but are also placing odds on how long he will be in power.
Odds that he will not complete his first term in office are at 5/2, while the odds of Trump being impeached during the first 6 months of his term are at 4/1.
The 2016 presidential election saw record high bets being placed on the outcome. Roughly $130 million was staked on the outcome of the election, according to Betfair.
Follow CNBC International on Twitter and Facebook.