Here's what they had to say:
Vladimir Putin, President of RussiaPutin congratulated Donald Trump on winning the U.S. presidential election in a telegram today, according to the Kremlin.
"Putin expressed hope for joint work to restore Russian-American relations from their state of crisis, and also to address pressing international issues and search foreffective responses to challenges concerning global security," the Kremlin said in a statement.
Putin also said he was confident that a constructive dialogue between Moscow and Washington would serve the interests of both countries, the Kremlin added.
In the past, Trump has praised Putin, saying that he would have a "very, very good relationship with Putin" as president.
"The man has very strong control over a country," Trump said at forum on national security in September. "Now, it's a very different system and I don't happen to like the system, but certainly in that system, he's been a leader. Far more than our president [Obama] has been a leader. We have a divided country."
Theresa May, Prime Minister of the U.K.In a statement today, May said she "would like to congratulate Donald Trump on being elected the next President of the United States, following a hard-fought campaign."
"Britain and the United States have an enduring and special relationship based on the values of freedom, democracy and enterprise," she said. "We are, and will remain, strong and close partners on trade, security and defence."
May added, "I look forward to working with President-elect Donald Trump, building on these ties to ensure the security and prosperity of our nations in the years ahead."
Ashraf Ghana, President of AfghanistanGhana said in statement today that he congratulated Trump on behalf of his government and of the people of Afghanistan.
He added that the U.S. is an "essential and important strategic partner to Afghanistan in development of the country and fighting terrorism."
Abdel Fatah al-Sisi, President of EgyptFatah al-Sisi wished Trump "success in serving the friendly American people, who gave him their trust to lead them" and said in a statement that he looked forward to reinvigorating US-Egyptian ties.
Narendra Modi, Prime Minister of IndiaModi congratulated Trump via Twitter today, saying, "We appreciate the friendship you have articulated towards India during your campaign."
He added, "We look forward to working with you closely to take India-US bilateral ties to a new height."
Mahmoud Abbas, President of PalestineAbbas congratulated Trump in a statement today. He added that he "hopes that peace will be achieved during his term".
Shinzo Abe, Prime Misister of JapanAbe congratulated Trump in a statement today, adding that the "stability of the Asia-Pacific region, which is a driving force of the global economy, brings peace and prosperity to the United States" and that "Japan and the United States are unwavering allies tied firmly with the bond of universal values such as freedom, democracy, basic human rights, and the rule of law"
Abe added that he "very much" looked forward "to closely cooperating" with Trump "to further strengthen the bond of the Japan-U.S. Alliance, as well as for our two countries to play leading roles for assuring peace and prosperity in the Asia-Pacific region."
Malcolm Turnbill, Prime Minister of AustraliaTurnbull of Australia congratulated Trump via a video posted to Twitter today.
"Americans have no stronger ally than Australia," he said.
John Key, Prime Minister of New ZealandKey congratulated Trump on Twitter today, saying, "The American people have spoken."
Justin Trudeau, Prime Minister of Canada"Canada has no closer friend, partner, and ally than the United States," Trudeau said in a statement. "We look forward to working very closely with President-elect Trump, his administration, and with the United States Congress in the years ahead, including on issues such as trade, investment, and international peace and security."
Benjamin Netanyahu, Prime Minister of Israel"President-elect Trump is a true friend of the State of Israel," Netanyahu said. "We will work together to advance the security, stability and peace in our region. The strong connection between the United States and Israel is based on shared values, shared interests and a shared destiny."
Donald Tusk, President of the European Council, and Jean-Claude Juncker, President of the European CommissionTusk and Juncker offered their "sincere congratulations" to Trump in a letter posted to Twitter.
The two invited the President-elect to visit Europe "for an EU-US Summit at your earliest convenience."
Jens Stoltenberg, Secretary General of the North Atlantic Treaty Organization (NATO)"I congratulate Donald Trump on his election as the next President of the United States," Stoltenberg said in a statement today. "And I look forward to working with President-elect Trump."
Stoltenberg said that "US leadership is as important as ever" as the world faces "a challenging new security environment, including hybrid warfare, cyber attacks."
He added that a "strong NATO is good for the United States, and good for Europe."