The outcome of the election was watched particularly closely in the UK, which has seen its own political upset this year in the form of the vote to leave the European Union in June. Both votes are seen as an anti-establishment, anti-elite backlash.
British Prime Minister Theresa May has previously criticized Trump. During his campaign, when she was still Home Secretary, she hit back at his claim that parts of the UK were "no-go zones" because of Islamic extremism. She said then that he was "absolutely wrong," warning that politicians should be "bringing greater cohesion in communities, not seeking to divide." On Wednesday, however, she struck a more conciliatory note, saying in a statement: "We are, and will remain, strong and close partners on trade, security and defense."
It fell to other politicians to express the anxieties felt by many Britons. "This is a devastating day for women, for people of color, for disabled people and for an inclusive society in the USA," said Green Party co-leader Caroline Lucas. "Trump's election is also a hammer blow for the fight against climate change - and presents a genuine threat to some of the poorest people in the world who will suffer its effects worse."
While May stressed the 'special relationship' in her statement, it is unclear what that will look like under Trump. Nigel Farage, leader of the UK Independence Party (Ukip) and a key figure in the Brexit debate, has been campaigning for Trump. Earlier this year, Trump called for Britain to leave the EU, saying "what do you need it for?," and promised that the UK would be "treated fantastically" after Brexit.
This was a direct contrast to current president Barack Obama, who warned that Britain would go to the "back of the queue" for any US trade deal if it left the EU. For those Conservative politicians lobbying for a hard Brexit from the single market, Trump's victory may increase hopes of a good trade deal. "You would certainly not be back of the queue, that I can tell you," he said earlier this year.
Whatever the outcome, however, the market uncertainty emanating from Trump's victory will impact Britain. "The resilience of British companies will be tested by market and currency volatility in coming days and the country will need the perseverance and fortitude of business leaders," Simon Walker, Director General of the Institute of Directors, a body of business leaders, told DW.
Trump has also argued vociferously against free trade, in a radical break with Republican tradition. "During the US election the benefits of free trade came under attack from both candidates, a development which has worried the business community," Walker added. "In today's globalized world, pulling up the drawbridge and turning inwards will only hurt citizens. We can only hope that as President, Trump will embrace the USA's role as a leader in international economic cooperation."
Concerns have also been raised in the UK about the future of the NATO alliance, which Trump has questioned, and about Trump's apparent admiration of Russian President Vladimir Putin at a time of rising tensions in Europe. "I felt emotional after the Brexit result, but today I feel genuinely afraid," says London resident Florence Parker. "The president holds so much power not just over the US, but over the whole world. This could entirely change the dynamics of different foreign policy relationships in ways we haven't even predicted yet," she told DW.
The Brexit vote in the UK saw a surge in racist and xenophobic hate crimes, with concerns raised about the legitimizing of racist rhetoric during the campaign. These worries about bigoted discourse mirror the result in America - which was welcomed by former KKK leader David Duke.
"Donald Trump used the oldest trick in the book - he stirred up fear and racism in the context of a stagnant economy and the resulting fall in living standards - to mobilize a vote for him," said Sabby Dhalu, co-convener of Stand up to Racism, a group which was planning to hold an anti-racism protest outside the US Embassy in London later on Wednesday. "The danger now is racists across the globe feel emboldened by Trump's victory and racism and sexism become normalized through the most powerful figure in the world," Dhalu told DW.
Many people in Britain see this as a potentially seismic shift. "This is a tragedy, not only for America, but for liberal politics globally," says Owen Kean, from Liverpool. "I fear that the march of the right, of racist politics masquerading as anti-establishment sentiment, will continue unhindered around the world. The domino effect of Brexit and Trump threatens all of western civilization: a commitment to pluralism, to equality, and to helping those in need. The world took a step back last night, our job as liberals is to make sure the next step, for our country and the world, is forward," he told DW.