During his victory speech delivered shortly after his triumph had been proclaimed, he broke with his usual campaign rhetoric of slamming Hillary Clinton and hyperbole, instead choosing to congratulate his opponent on her election campaign and telling his raucous audience "we owe her a major debt of gratitude" for her prolonged period of time in civil service.
Clinton called Trump in the early hours of Wednesday to concede the election after he won 288 of the electoral votes—18 more than the necessary 270—making it impossible for her to win.
As the tycoon-turned-politician continued his speech, he called on even those who did not support him to offer their guidance and to “help to work together to unify the US.” In that vein, he said that it’s "time for us to come together," and pledged to be president "for all Americans."
Thanking each member of his family for their support throughout the bruising campaign, Trump told the elated crowds that “the forgotten men and women of America will be forgotten no longer.”
With investors worried a Trump victory could cause economic and global uncertainty, investors fled risky assets such as stocks. In overnight trading, S&P 500 index futures fell 5 percent to hit their so-called limit down levels, indicating they would not be permitted to trade any lower until dayside trading resumed on Wednesday morning.
Seeking to allay the fears which he had aroused throughout the world during his bid for the White House that his presidency could spell unfavorable treatment for both friends and foe alike, Trump reached out to the international community, promising that he would “deal with everyone fairly.”
Shortly after networks called Wisconsin for Trump on Tuesday evening, celebrating supporters at his election night rally in New York began to chant "lock her up" - a common refrain on the campaign trail for the former US secretary of state repeatedly branded "Crooked Hillary" by the volatile Trump.
A packed crowd in the lobby of Trump's new hotel in Washington, DC, also broke into chants of "lock her up" and "USA, USA, USA" as state after state was called for Trump.
Republicans also were projected to maintain control of the US House of Representatives and the Senate, making it easier on Trump to enact his agenda with a Republican-led Congress.
As the evening wore on, Clinton, 69, acknowledged the unexpectedly close results given her lead in opinion polls going into Election Day.
"This team has so much to be proud of. Whatever happens tonight, thank you for everything," Clinton said on Twitter.
A wealthy real-estate developer and former reality TV host, the 70-year-old Trump rode a wave of anger toward Washington insiders to challenge Clinton, whose gold-plated establishment resume includes stints as a first lady, US senator and secretary of state.
However, both candidates had historically low popularity ratings, although Trump's were worse than Clinton's, in an election that many voters characterized as a choice between two unpleasant alternatives.
Before Tuesday's voting, Clinton led Trump, 44 percent to 39 percent in the last Reuters/Ipsos national tracking poll. A Reuters/Ipsos States of the Nation poll gave her a 90 percent chance of defeating Trump and becoming the first woman elected US president.
A Reuters/Ipsos national Election Day poll offered some clues to Clinton's weakness. It found she underperformed expectations with women, winning their vote by only about 7 percent, similar to President Barack Obama when he won re-election in 2012.
And while she won Hispanics, black and millennial voters, Clinton did not win those groups by greater margins than Obama had in 2012. Younger blacks did not support Clinton like they did Obama, as she won eight of 10 black voters between the ages of 35 and 54. Obama won almost 100 percent of those voters in 2012.
As Trump's chances of winning the presidency increased, Mexico's peso plunged to its lowest-ever levels. Concerns of a Trump victory have weighed heavily on the peso for months because of his threats to rip up a free trade agreement with Mexico and tax money sent home by migrants to pay to build a wall on the southern US border.
In a presidential campaign that focused more on the character of the candidates than on policy, Clinton and Trump accused each other of being fundamentally unfit to lead the country.
Trump entered the race 17 months ago and defeated a field of some 16 rival Republican candidates in the primary contests to win his party's presidential nomination.
He survived a series of seemingly crippling blows, many of them self-inflicted, including the emergence in October of a 2005 video in which he boasted about making unwanted sexual advances on women. He apologized but within days, several women emerged to say he had groped them, allegations he denied.
He was judged the loser of all three presidential debates with Clinton and she led him by varying margins for months in opinion polls.
Trump won avid support among a core base of white non-college educated workers with his promise to be the "greatest jobs president that God ever created." He has vowed to impose a 35 percent tariff on goods exported to the United States by US companies that went abroad.
His unpredictable nature, frequent insults and unorthodox proposals led to campaign feuds with a long list of people, including Muslims, the disabled, Republican US Senator John McCain, Fox News anchor Megyn Kelly, the family of a slain Muslim-American soldier, a Miss Universe winner and a federal judge of Mexican heritage.