Clinton, fresh off the news that the FBI didn't recommend charges against her for using a private email server for government correspondence when she was secretary of state, took the stage first to chants of "Hillary, Hillary, Hillary." She said she has known Obama in many roles and called him "a friend."
"I was honored to stand with him in the good times and the hard times," she told the crowd in Charlotte. "Someone who has never forgotten where he came from. And Donald [Trump], if you're out there tweeting, it's Hawaii."
Clinton smiled after her reference to the Trump-led birther movement, which questioned whether Obama was born in the United States.
Clinton spoke first and then introduced Obama, who spoke for almost twice as long as the presumptive Democratic nominee.
"Everybody can tweet. Nobody actually knows what it takes to do the job until you sit behind the desk," said the president, making a veiled reference to Trump. "Sasha tweets, but she doesn't think that she thereby should be sitting behind the desk."
Obama called Clinton "steady and true" and said she's in politics for the same reason he is, to help others. He took a swipe at Republicans who "don't really know what the guy is talking about," making another reference to Trump.
"You ask them, they're all like, 'I don't know.' Then they kinda duck the other way. Am I joking? No." Going a step further, Obama told the crowd in North Carolina, a battleground state, that "this isn't even a choice because the other side has nothing to offer you."
When the crowd booed as Obama made reference to the presumptive GOP nominee, the president shot back, "Don't boo, vote."
During her remarks, Clinton looked back to 2008, when she played an active role campaigning for Obama after he defeated her in the primary contest.
Obama took the stage to Clinton's asking the crowd if they were "fired up and ready to go."
He said, "Fired up? I am. I'm fired up. Hillary got me fired up. She got me ready to do some work."
"There has never been any man or woman more qualified for this office than Hillary Clinton. Ever," he said. "And that is the truth. That is the truth."
Obama, who has only six months left in office, reflected on going "toe to toe" with Clinton from "coast to coast" and commended her performance as his secretary of state.
"So the bottom line is, I know Hillary can do the job," he said. "And that's why I am so proud, North Carolina, to endorse Hillary Clinton as the next president of the United States."