President of the European Commission José Manuel Barroso said the Yes vote was a great day for Ireland and for Europe.
'I see the Yes vote as a sign of confidence by the Irish electorate in the European Union, as a sign of their desire to be wholehearted members at the heart of the European Union, as a sign that Ireland recognises the role that the European Union has played in responding to the economic crisis,' Mr Barroso said.
The newly re-elected Commission President said the guarantees given by Europe to Ireland had played a significant role in meeting the concerns of many people and had shown that Europe listened and reacted.
Ireland voted in favour of theTreaty by a margin of 67.1% to 32.9%.
As the news of a Yes vote emerged, President of the European Parliament Jerzy Buzek said ‘it is not the end of the story. Now we must start to work to overcome the difficulties.'
'Our citizens are afraid of the energy issue, the unemployment rate, about immigration, demography and we can do that together, as it was before, also in the future, in solidarity.'
Swedish Foreign Minister Carl Bildt, whose country currently holds the EU presidency, said 'we can finally push the button for the better European cooperation that the Lisbon Treaty can give us.'
However, Czech President Vaclav Klaus said the Irish result was 'tarnished since this is a repeated referendum'.
Britain's Prime Minister Gordon Brown said the result was good for the UK and Europe.
Mr Brown said Europe can ‘work together to focus on the issues that matter most to Europeans - a sustained economic recovery, security, tackling global poverty, and action on climate change’.
But, UK Independence Party leader Nigel Farage, who entered the debate calling for a No vote, compared the Lisbon Treaty referendum with a corrupt election in Zimbabwe or Afghanistan.
The MEP for South East England said there was a 'wall of money' for the Yes campaign, and blamed High Court judgments and broadcasting laws for conspiring against the anti-Lisbon side.
‘The Irish have been bullied into voting Yes,’ he said.