US President, Barack Obama
"The people of the United Kingdom have spoken, and we respect their decision," Obama said in a statement. "The United Kingdom and the European Union will remain indispensable partners of the United States even as they begin negotiating their ongoing relationship."
British Prime Minister, David Cameron
"I do not think it would be right for me to try to be the captain that steers our country to its next destination ... it is in the national interest to have a period of stability and then the new leadership required."
Russian President, Vladimir Putin
"I think it is understandable why this happened: first, no one wants to feed and subsidise weaker economies ...second, people are apparently dissatisfied with the resolution of security issues, which has become more acute against the background of powerful migration processes."
Chinese fogeign ministry spokeswoman, Hua Chunying
"The impact will be on all levels, not only on relations between China and Britain ... China supports the European integration process and would like to see Europe playing a proactive role in international affairs."
US Republican presidential candidate, Donald Trump
"They took back control of their country. It's a great thing ...people are angry, all over the world ...they're angry over borders, they're angry over people coming into the country and taking over. Nobody even knows who they are. They're angry about many, many things."
"It was the will expressed by the people and this requires a great responsibility on the part of all of us to guarantee the good of the people of the United Kingdom, as well as the good and co-existence of the European continent."
World Trade Organisation director, general Roberto Azevedo
"The WTO stands ready to work with the UK and the EU to assist them in any way we can," WTO director-general Roberto Azevedo said on Twitter.
Azevedo warned in a speech this month that British business competitiveness would suffer if Britons voted to leave the European Union. "While trade would continue, it could be on worse terms," he said at the time of a vote to leave the EU.
He has already said that Britain would have to renegotiate its relationship with the rest of the WTO, which could take years or decades.
EU foreign policy head, Federica Mogherini
"We will continue to act as a force for peace, a provider of security, and a staunch supporter of international cooperation and multilateralism," Federica Mogherini said, adding she regretted Britain's decision to leave.
European Council President, Donald Tusk
"We are determined to keep our unity as 27 ... I will propose that we start a period of wider reflection on the future of our union."
Leading figure in "Leave" campaign, Boris Johnson
"We can find our voice in the world again, a voice that is commensurate with the fifth-biggest economy on Earth ... I believe we now have a glorious opportunity: we can pass our laws and set our taxes entirely according to the needs of the UK economy ...
"There is now no need for haste and ... nothing will change over the short term."
German chancellor, Angela Merkel
"We have to recognise the decision of the majority of the British people with deep regret today. There is no point beating about the bush: today is a watershed for Europe, it is a watershed for the European unification process."
French President, Francois Hollande
"Europe must act quickly where it's needed and must, once and for all, let member states handle what is their exclusive domain."
French Prime Minister, Manuel Valls
"It's an explosive shock. At stake is the break-up pure and simple of the union. Now is the time to invent another Europe."
Norwegian Prime Minister: Erna Solberg
Solberg called the vote a "signal from both the British voters and many other voters around Europe who feel that the EU is not providing good enough answers to today's challenges".
Hungarian Prime Minister, Viktor Orban
"Brussels must hear the voice of the people, this is the biggest lesson from this decision."
"Europe is strong only if it can give answers to major issues such as immigration that would strengthen Europe itself and not weaken it. The EU has failed to give these answers."
Polish President, Andrzej Duda
"Everything must be done to prevent other countries leaving."
Italian Prime Minister, Matteo Renzi
"We have to change (the EU) to make it more human and more just, but Europe is our home, it's our future."
Acting Spanish Prime Minister, Mariano Rajoy
"In little more than half a century, Europeans have built the greatest space for peace, freedom and prosperity in all of humanity’s history. And, despite the serious setbacks like the one we face today, nobody should doubt that we are going to continue working to build tomorrow."
Swedish EU Minister, Ann Linde
"We must show people why we believe the EU is important, why we need to remain. We have to look at the things that matter in people's everyday lives, perhaps where there have been ambiguities, where there's been arrogance and where people have felt it's been an elite project."
Greek Prime Minister, Alexis Tsipras
"We urgently need a new vision and beginning for a united Europe - for a better Europe, more social and democratic."
First minister of Scotland, Nicola Strugeon
"I think an independence referendum is now highly likely ... intend to take all possible steps and explore all options to give effect to how people in Scotland voted, in other words to secure our continuing place in the EU and in the single market."
Nationalist deputy first minister of Northern Ireland, Martin Mcguinness
"The British government now has no democratic mandate to represent the views of the North in any future negotiations with the European Union and I do believe that there is a democratic imperative for a 'border poll' to be held."
United Nations Secretary-General, Ban-Ki-Moon
The UN Secretary-General expects Britain to continue its leadership at the world body particularly on development issues after the country, a Security Council veto power, voted to leave the European Union.
"At the UN, we look forward to continuing our work with the United Kingdom and the European Union, both important partners," Ban's spokesman Stephane Dujarric said in a statement on Friday. "When we work together, we are stronger."
He said that as Britain and the European Union begin to negotiate a departure, Ban "trusts in Europe's well-proven history of pragmatism and common responsibility in the interest of European citizens".
International Monetary Fund Managing Director, Christine Lagarde
On Friday Lagarde urged British and European authorities to work towards a smooth transition implementing Britons' vote to leave the European Union.
"We take note of the decision by the people of the United Kingdom," Lagarde said in a statement. "We urge the authorities in the UK and Europe to work collaboratively to ensure a smooth transition to a new economic relationship between the UK and the EU, including by clarifying the procedures and broad objectives that will guide the process."
"We strongly support commitments of the Bank of England and the ECB to supply liquidity to the banking system and curtail excess financial volatility. We will continue to monitor developments closely and stand ready to support our members as needed," Lagarde added.