Democrat Barack Obama won an extraordinary two-year struggle for the White House, beating Republican John McCain to become the first black president in US history.
Quotes from world leaders:
Brian Cowen, An Taoiseach
Taoiseach Brian Cowen has sent a message of congratulations to Barack Obama on his election as the 44th President of the United States.
He said that 'Barack Obama's remarkable personal story - allied to his eloquence and his huge political talents - sends a powerful message of hope to America's friends across the world.'
He added that he looks forward to 'the President-elect building on America's strong relationships with the EU and other countries around the globe.'
The Taoiseach also formally invited President-elect Obama to visit Ireland and his ancestral home in Co Offaly.
President Mary McAleese
President McAleese has this morning warmly congratulated Barack Obama following his historic election victory.
She said that she wishes Senator Obama every good fortune in the most demanding role of President of the United States of America.
She continued; 'the election of Senator Obama was transformational in its power and scope, and serves as a beacon of hope, not just in America, but around the world, particularly in these turbulent times of anxiety and uncertainty.'
'I hope he will be successful in charting a new and dynamic course for America in what will inevitably be a challenging and crucially important period in office.'
Nelson Mandela, Fmr South African President
Former South African President Nelson Mandela has praised Barack Obama's victory in the US presidential election and urged him to fight poverty and disease throughout the world.
'Your victory has demonstrated that no person anywhere in the world should not dare to dream of wanting to change the world for a better place,' the anti-apartheid icon wrote to Obama in a letter released by the Nelson Mandela Foundation.
'We note and applaud your commitment to supporting the cause of peace and security around the world. We trust that you will also make it the mission of your Presidency to combat the scourge of poverty and disease everywhere.'
Nicolas Sarkozy, French President
'With the world in turmoil and doubt, the American people, faithful to the values that have always defined America's identity, have expressed with force their faith in progress and the future.
At a time when we must face huge challenges together, your election has raised enormous hope in France, in Europe and beyond. France and Europe...will find a new energy to work with America to persevere peace and world prosperity.'
Hamid Karzai, Afghan President
'I applaud the American people for their great decision and I hope that this new administration in the United States of America, and the fact of the massive show of concern for human beings and lack of interest in race and colour while electing the president, will go a long way in bringing the same values to the rest of world sooner or later.'
Amr Mussa, Arab League Secretary General
Barack Obama's US presidential victory is 'a historic day' for the Middle East and nations in the region hope he will prove to be an 'honest broker', Arab League chief Amr Mussa said.
'We should seize the opportunity to express congratulations and in stressing the importance of this day,' said Mussa in an address to the European Parliament's foreign affairs committee.
'I also stress the importance of the message that Mr Obama has never ceased to send, which is we all need change and that is what we do expect from the new leader of the United States,' he added.
Mwai Kibaki, Kenyan President
'We the Kenyan people are immensely proud of your Kenyan roots. Your victory is not only an inspiration to millions of people all over the world, but it has special resonance with us here in Kenya.'
Stephen Harper, Canadian Prime Minister
'I look forward to meeting with the President-elect so that we can continue to strengthen the special bond that exists between Canada and the United States.
Ministers in our government look forward to building a strong working relationship with their counterparts in a new Obama cabinet.'
Jose Manuel Barroso, European Commission President
'We need to change the current crisis into a new opportunity. We need a new deal for a new world. I sincerely hope that with the leadership of President Obama, the United States of America will join forces with Europe to drive this new deal. For the benefit of our societies, for the benefit of the world.'
Taro Aso, Japanese Prime Minister
'The Japan-US alliance is key to Japanese diplomacy and it is the foundation for peace and stability in the Asia-Pacific region. With President-elect Obama, I will strengthen the Japan-U.S. alliance further and work towards resolving global issues such as the world economy, terror and the environment.'
Kgalema Motlanthe, South African President
'Africa, which today stands proud of your achievements, can only but look forward to a fruitful working relationship with you both at a bilateral and multilateral levels in our endeavour to create a better world for all who live in it.
We express the hope that poverty and under-development in Africa, which remains a challenge for humanity, will indeed continue to receive a greater attention of the focus of the new administration.'
Helen Clark, New Zealand Prime Minister
'Senator Obama will be taking office at a critical juncture. There are many pressing challenges facing the international community, including the global financial crisis and global warming. We look forward to working closely with President-elect Obama and his team to address these challenges.'
Susilo Bambang Yudhoyono, Indonesian President
'Indonesia especially hopes that the U.S., under new leadership, will stand in the front and take real action to overcome the global financial crisis, especially since the crisis was triggered by the financial conditions in the US'
Saeb Erekat, Aide to Palestinian President Mahmoud Abbas
'We hope the president-elect in the United States will stay the course and would continue the U.S. engagement in the peace process without delay. We hope the two-state vision would be transferred from a vision to a realistic track immediately.'