- From the section US & CanadaImage caption
But as he and his team prepare to take power he has shifted his stance on a number of key issues.
Prosecuting Hillary ClintonBefore: "Lock her up" was one of the main rallying cries of Mr Trump's supporters.
They wanted to see Democratic rival Hillary Clinton in prison over the use of her private email server while secretary of state.
And Mr Trump was more than willing to back their calls for, at the very least, a fresh investigation. During the debates, he told Mrs Clinton: "If I win, I am going to instruct my attorney general to get a special prosecutor to look into your situation."
After: The President-elect's tone changed almost as soon as he had won, describing the woman he had said was "such a nasty woman" as someone the country owed "a debt of gratitude". Later, he said he "hadn't given [the prosecution] a lot of thought" and had other priorities.
And in an interview with 60 Minutes, he said he was "going to think about it", adding: "They're good people. I don't want to hurt them."
ObamacareBefore: Another of Mr Trump's pet hates was Obamacare - his predecessor's attempt to extend healthcare to the estimated 15% of the country who are not covered.
It is widely hated by Republicans, who say the law imposes too many costs on business, with many describing it as a "job killer" and decrying the reforms - officially the Affordable Care Act - as an unwarranted intrusion into the affairs of private businesses and individuals.
After: Mr Trump had repeatedly promised to repeal and replace the act, but within two days of his election he softened his approach.
He said he had reconsidered repealing the entire act after meeting with Mr Obama, telling CBS he wanted to keep the "strongest assets".
According to Mr Trump these are the ban on insurers denying coverage for pre-existing conditions and allowing young adults to be insured on their parents' policies.
'The Wall'Before: His vow to build a wall along the US-Mexican border was one of the most controversial of Mr Trump's campaign promises.
Mr Trump also insisted that the Mexico would pay for it.
After: Rudy Giuliani, one of his closest advisors, has said it will be built - even if he has to sign it through as an executive order - as Mr Trump "isn't going to break a campaign promise".
The scheme has been scaled back though - Mr Trump has already admitted some parts will be fenced. And one of his supporters tipped to be the next secretary of state, Newt Gingrich, told NPR the idea was just a device to get elected.
"He may not spend much time trying to get Mexico to pay for it. But it was a great campaign device," Mr Gingrich said.
Mr Trump's website, however, suggests he is still planning on making Mexico pay for the wall. The Mexicans, on the other hand, have made it quite clear they will not be paying.
Ban on MuslimsBefore: Mr Trump initially promised to ban all Muslims entering the US, but switched to "extreme vetting" after he became the party's presidential candidate.
In a campaign statement in December 2015, he said a "total and complete" shutdown should remain until the US authorities "can figure out" Muslim attitudes to the US.
In August 2016, he said he would enact "extreme vetting" of immigrants.
After: The immigration section of Mr Trump's website makes no mention of this pledge.
Instead, Mr Trump has replaced the policy with one suspending visas "to any place where adequate screening cannot occur, until proven and effective vetting mechanisms can be put into place".
Mr Giuliani said an outright ban on any Syrians entering the country would remain, however.
Deporting all illegal immigrantsBefore: Mr Trump repeatedly told his supporters that every single undocumented immigrant - of which there are 11.3 million - "have to go".
After: As polling day approached, his stance began to soften slightly.
On Sunday, he confirmed the plan had been scaled back somewhat - albeit to some two to three million deportations of people who "are criminal and have criminal records, gang members, drug dealers".
He may still struggle to find two to three million illegal immigrants in the US. The Migration Policy Institute, a US-based think tank, has one of the higher figure for illegal immigrants with criminal records, which it puts at 890,000, including people charged with crossing the border illegally.
Where Trump has not softened
- Abortion: Mr Trump has said he is pro-life, and future appointments to the Supreme Court would be as well. This could mean Roe v Wade may be revoked, making abortion harder to access.
- Global warming: Mr Trump wants to cancel payments to UN climate change programs. He also wants to lift production limits on coal production and indicated he will withdraw from the Paris agreement.
- Trade deals: Mr Trump vowed to renegotiate the North American Free Trade Agreement (Nafta), and withdraw from the Trans Pacific Partnership, a deal currently under negotiation with Europe.
- Label China a currency manipulator: Mr Trump has vowed to do this on his first day in office.