"President Barack Obama was born in the United States, period," Trump said at the Trump International Hotel in Washington D.C.
Trump also made a claim -- which has been proven false -- that Clinton and her 2008 campaign started the birther movement when she was running against then-Senator Obama for the presidency.
However, as recently as yesterday, Trump refused to acknowledge that the president is a native-born American citizen. Obama was born in Hawaii.
In an interview with the Washington Post published Thursday night, Trump, when asked if he believed the president was born in the U.S., said he would "answer that question at the right time. I just don’t want to answer it yet.”
Trump’s acknowledgement Friday morning of the fact that Obama is native-born comes after several people in his campaign, including campaign manager Kellyanne Conway and running mate Mike Pence, have gone on the record saying the candidate believes Obama was born in the United States.
The Trump campaign also released a statement Thursday night -- from a campaign spokesman -- saying the candidate believes Obama was born in America and that he had "successfully obtained President Obama’s birth certificate when others could not."
Clinton campaign manager Robby Mook called Trump's remarks Friday "disgraceful," "appalling" and "sickening."
"Trump’s actions today were disgraceful," Mook said in a statement. "After five years of pushing a racist conspiracy theory into the mainstream, it was appalling to watch Trump appoint himself the judge of whether the President of the United States is American. This sickening display shows more than ever why Donald Trump is totally unfit to be president."
The White House released Obama’s birth certificate in April 2011 to put an end to the conspiracy theories, but over the years Trump still voiced doubt about the document's authenticity.
In a 2013 interview with ABC News’ Jonathan Karl, the real estate mogul said, “Well, I don't know, was there a birth certificate? You tell me. You know some people say that was not his birth certificate. So maybe it was; maybe it wasn't.”
Hillary Clinton on Friday attacked Trump on his history of questioning whether the president is native-born. Speaking at the Black Women’s Agenda annual symposium, the Democratic nominee said that for five years Trump “led the birther movement to delegitimize our first black president.”
When asked for his response to the Trump campaign finally acknowledging he was born in the U.S., President Obama told ABC News' Jonathan Karl he was "shocked" such a question was being asked.
Elsewhere in Washington, DC on Friday, members of the Congressional Black Caucus excoriated Trump, taking turns pummeling the GOP nominee for leading the movement questioning President Obama's birth.
"Donald Trump is a disgusting fraud," said Rep. GK Butterfield, D-North Carolina, the chairman of the caucus. "He is an insult to the intellect of the American people."
ABC’s Benjamin Siegel contributed reporting.