Brian France, the racing association's CEO, appeared Monday alongside Trump during a rally at Valdosta State University, touting the Republican front-runner's success in his business and personal life.
"You know about his winning in business and success. I'm gonna tell you, he wins with his family," said France, who noted that he's known Trump for more than two decades.
"That's how I judge a winner," France added, pointing to how well Trump's children have turned out.
The endorsement marked a stark contrast with how NASCAR reacted to Trump's controversial comments this summer about undocumented Mexican immigrants -- calling them criminals and "rapists" -- when the racing association decided to change the location for its postseason banquet away from the Trump National Doral and to another venue.
Bill Elliott, a retired champion NASCAR driver, also joined Trump on stage, saying that he's "all for" what Trump has said he will do for the United States as president.
"For what he can do I think for our country, I'm all for it. We need a change guys, that's all there is to it," Elliott said.
Elliott's son and two other current NASCAR drivers also endorsed Trump Monday.
The endorsements could give Trump a boost Tuesday, when more than a dozen states, including several southern states like Georgia, where NASCAR is especially popular, make their choice for Republican nominee known.
NASCAR's 2015 season averaged 5.1 million viewers, according to the ESPN-owned Jayski.com website.
Thanking his latest endorsers, Trump noted that "they have guts."
Moments earlier, Trump opened his rally praising the stock car racing association.
"I love NASCAR. Do we love NASCAR?" Trump asked the crowd.
The endorsement comes on the heels of a series of high-profile endorsements for the billionaire Republican presidential candidate who is increasingly viewed as most likely to become his party's nominee.
New Jersey Gov. Chris Christie and Alabama Sen. Jeff Sessions have also endorsed Trump in the final days of campaigning leading up to the crucial Super Tuesday contests.