President McAleese and Taoiseach Brian Cowen have led congratulatory messages from Ireland to Barack Obama on his election as the 44th President of the United States.
President McAleese wished Senator Obama "every good fortune in the most demanding role of President of the United States of America".
Describing Senator Obama's election as "transformational in its power and scope", Ms McAleese said it served as "a beacon of hope, not just in America, but around the world".
In a goodwill message to Mr Obama this morning, Mr Cowen extended an invitation to the successful Democratic candidate to visit Ireland and his ancestral homeland of Moneygall, Co Offaly.
The Taoiseach said he was looking forward to working with Mr Obama on issues of mutual interest to Ireland and to "building on the existing deep and cherished ties between our two countries".
Mr Obama's election as the first black president of the United States, Mr Cowen said, has created a "a palpable sense of history".
"On this day, we are all reminded of those who struggled for civil rights in America for so many years, as well as all of those who work for justice and peace around the world today," the Taoiseach said.
"At a time of immense global challenges, today is a day of hope for the world,” Mr Cowen added.
The Taoiseach also formally invited US president-elect Obama to visit Ireland and his ancestral home in County Offaly where local Church of Ireland rector Stephen Neill recently found evidence that Mr Obama’s fourth great-grandfather was a shoemaker in the village of Moneygall.
Green Party leader and Minister for the Environment John Gormley also offered his congratulations to the president-elect this morning.
Mr Gormley said Mr Obama "has an unprecedented opportunity to demonstrate global leadership" and added that he was encouraged by his policy pledges on climate change and energy issues.
Minister for Integration Conor Lenihan said Mr Obama's victory would be an inspiration to all people, "especially those of African origin here in Ireland, many of whom stayed up late into the early hours to witness his election".
"Hopefully it will encourage people from an immigrant background to become more involved in politics by registering to vote in next year's local elections," he added.
Fine Gael Leader Enda Kenny said the Obama win had “profound implications for governance in many countries.
“Barack Obama epitomises the hopes of a new generation and the realisation of lost opportunities for older people. Most of all, he has tapped into and redirected the frustration of millions of people into the Democratic cause."
Labour leader Eamon Gilmore said Mr Obama’s victory “will now open a new and more hopeful chapter for the American people and the people of the world”.
“My only concern about the new President is that some of the tax policies he advocated during the campaign may make it more difficult for US companies to invest in Ireland and thus jeopardise jobs in this country,” Mr Gilmore added.
“The Irish Government will need to make early contact with the new administration on this issue.”
Sinn Féin president Gerry Adams also offered his congratulations to Mr Obama on winning the US presidential
election.
"Barak Obama’s election shows in politics that change is possible, and people everywhere will be mindful of the long history of African Americans and of all those who struggled for justice and fairness." said Mr Adams.
