Already, about 12,000 people have signed up to see him, and that's not even including the thousands of people that will be there just to enjoy the fair.
“I have no idea where he's going to put all these people," said fair-goer Diane Pratte.
That's what a lot of folks are wondering.
Fair officials told NewsChannel 4 that, on an average Friday night, about 60-80,000 people visit the fair grounds.
So, they figure an additional 12,000 or so should not be a problem.
"We're very busy on a Saturday afternoon, a little less busy on a Friday night," said fair spokesperson Scott Munz. "This is just going to make Friday night like Saturday afternoon."
Just in case the crowd gets too large, the Oklahoma City Police Department will have more than 100 officers on the ground as well as looking down from safety towers.
"If, at some point, it does get to where it's unsafe, too many people at the fair, well, then, we'll make the call to maybe not allow any more people to attend or even shutting it down early if need be," said Capt. Paco Balderrama with OCPD.
Deputies, firefighters and EMSA will also be on-hand.
If you are not a fan of big crowds, police said you might want to choose a different night to go.
Something to remember, you must have a ticket to get into the fair, even if you registered to see The Donald.
Trump is scheduled to take the Bandshell Stage around 6:30 p.m Friday.
We will have live coverage of the speech on NewsChannel 4.
Also, feel free to join in on the conversation on Twitter by using #TrumpinOK