Ireland has been "humiliated" by the EU, Nigel Farage said.
The former Ukip leader called for a eurosceptic mobilisation to win votes off pro-EU politicians in the next European elections and said there was a democratic deficit in the national debate.
During his Dublin visit he recalled the austerity of the post-2008 European bailout of the Irish state and urged citizens to rebel against Brussels.
The MEP said: "What on earth is going on in the politics of this country?
"How much more humiliated can the Irish nation be than for years being run by the Troika?"
Ireland's spending plans were scrutinised by representatives of the European Commission, European Central Bank and IMF, known as the Troika, and strict spending cuts imposed.
Mr Farage added: "The indignity, a few years back, of your budget being seen by the German government before it was put to the Dail."
EU funding has helped Ireland overhaul its infrastructure and benefited its agriculture enormously.
Mr Farage said the country was not even a net beneficiary of EU funding any more.
He told a sizeable conference of supporters: "You are paying into the European budget and your Taoiseach said in Strasbourg the other week he is happy for Ireland to pay even more into the European budget.
"Are you pleased about that?"
Leo Varadkar said he was "open" to contributing more for things which advance the "European ideal" such as structural funds for Central and Eastern Europe to help them unlock economic potential.
Mr Farage said: "The perception of the media across Europe is that Ireland is very pro-European, very servile to the demands of Brussels.
"I don't think Ireland is a pro-EU country, I think the political, media and big businesses in Dublin, they are the ones."
He suggested it was Irish civil servants lining their pockets in Brussels who supported the EU.
To cheers he added: "They love it. They love it."
The crowd almost filled a hall at the RDS conference centre and gave Mr Farage a standing ovation.
He railed against the depiction of Brexiteers as xenophobes and bigots.
He said: "They go for the man and not for the ball."
Mr Farage said the European project was not going to work and the euro was unsuited to Ireland.
He added: "And yet I get told that Ireland is a very proud EU country, Michael O'Leary (Ryanair chief executive) told me so, it must be right.
"The euro has been bad for Ireland but a total catastrophe for countries like Greece."
He said there was an East/West split, with eurosceptic countries like Hungary leading the way.
"The EU will not work, it has not worked, it is increasingly unloved by the people of Europe," he said.