"If you want to let personalities get in your way of reality, you may. But I don't think that's wise," he said on "Squawk Box" in an interview from the Republican National Convention in Cleveland.
"This is about the future of America. I am an American. I am a Republican. And I'm on the team," the former Texas governor said despite his sharp criticisms of Trump on the campaign trail.
Perry said he's concerned about the economy, the shrinking military, border security and nominations to the Supreme Court. He said Trump is the best candidate to address those issues and put America on the right path.
"I'm a competitor. But I understand what 'team' means. And we all have to pull together and be part of the team. That's what made this pretty easy for me," Perry said, in reaction to the Bushes and Ohio Gov. John Kasich not supporting Trump.
"I'm never going to find the perfect candidate," Perry continued. "Trump was not my first choice. I was my first choice."
As for the No. 2 spot on the GOP ticket, he said Mike Pence was a "brilliant" choice as Trump's vice presidential running mate because the Indiana governor spent years on Capitol Hill and knows how to get legislation passed.
Pence is scheduled to speak at the convention Wednesday evening, and so is Texas Sen. Ted Cruz, whose candidacy was also unable to stop Trump.
After Perry dropped out of the race last year, becoming the first Republican hopeful to so so, he had supported Cruz. But Perry told CNBC he's all in for Trump now to prevent Clinton from winning.
Perry echoed remarks made Tuesday night by House Speaker Paul Ryan, who at times has been an uneasy ally of Trump.
Ryan said from the convention podium that Republicans need to come together and the GOP ticket offers a "better way" forward for the U.S. than Clinton. Ryan, the 2012 vice presidential nominee, is also the chairman of the GOP convention.