The rally is set to begin at 8.00pm local (1am BST).
The US President will also to speak at a private roundtable with supporters for a charity event.
It is Trump’s second visit to Indiana the May’s Senate primary to campaign against a senator he branded as “Sleeping’ Joe”.
The President wrote a tweet in support of Mr Braun on Thursday morning.
He wrote: “Will be going to Evansville, Indiana, tonight for a big crowd rally with Mike Braun, a very successful businessman who is campaigning to be Indiana’s next U.S. Senator.
“He is strong on Crime & Borders, the 2nd Amendment, and loves our Military & Vets. Will be a big night!”
Live updates from the rally can be found below. All times are in BST.
12.32am update: Red Hot Chilli Pipers concert CANCELLED due to Trump rally
A concert by the Red Hot Chilli Pipers has been cancelled because of the campaign rally being held by US President at the Ford Centre on Thursday night
12.26am update: People faint in scorching heat at packed rally
Emergency services have been called to the Donald Trump rally in Evansville, Indiana, after reports of people falling ill and fainting at the packed event.
The temperature has exceeded 32 degrees in Evansville today.
12.13am update: Donald Trump has arrived in Evansville
Trump arrived at Evansville Regional Airport at 5.30pm local time.
He was greeted by Mr Braun and his wife, Maureen, and by supporter Steve Chancellor and his wife, Terri.