There is no record of the communist firebrand, who died in 1924, ever travelling from Russia to Ireland.
Mr Kenny made the mistake last weekend at the Beal na mBlath ceremony in Cork, commemorating the 90th anniversary of Collins' death.
He referred to the former finance minister as "the outstanding organiser who brought Lenin himself to Ireland to see how the National Loan worked".
But last night, a spokesman for Mr Kenny admitted his script contained an inaccurate reference.
"It mistakenly stated that Lenin came to Ireland but should have stated that it brought Lenin's attention to Ireland to see how the National Loan worked," he said.
But Mr Kenny's department was unable to supply any historical records which showed that Lenin -- who was at that stagefighting a bloody civil war in the former Soviet Union -- had demonstrated any interest in the National Loan. And it would not say if the mistake was made by Mr Kenny himself or his speechwriter.
Historian Tim Pat Coogan, who wrote a best-selling biography of Michael Collins, questioned how the Lenin reference got into Mr Kenny's speech.
"I'm not aware that Lenin ever visited Ireland, let alone under the tutelage of Michael Collins," he said.
Mr Coogan pointed out that any such meeting between Collins and Lenin would have been extremely controversial, given the Catholic Church's hostility to Soviet communism.
"Those were the days when bishops were bishops and Lenin was a communist. How would that have gone down with the churchyard collections?
And he said it could also have been used by the British government to discredit the IRA's campaign during the War of Independence as a drive to turn Ireland into a communist state.
Historians have praised Collins for the success of his project to raise funds for the Irish state, while simultaneously holding four major roles in a full-scale guerrilla war.
He was minister for finance in the first Dail, director of intelligence for the IRA, president of the secret Irish Republican Brotherhood organisation and the creator of the "Squad", which killed British agents.
And he was responsible for advertising the National Loan, asking sympathisers for money and issuing personal receipts to people who contributed.
The scheme was used to fund the IRA's war against the British administration and raised around £370,000 in Ireland -- an enormous sum at the time.
But Mr Kenny's blooper may have been due to a mix-up about an even more colourful event. The Provisional Irish Government gave a $25,000 loan to Lenin's cash-strapped Russian regime in 1920, and got the Russian crown jewels as security.
Mr Coogan said that the Russian loan was organised by Pat McCartan, who was working as an envoy in the US. "It wasn't a Collins manoeuvre. They contacted us and they wanted loans, and Eamon de Valera wanted something for it," he said.
The Russian crown jewels were handed over in the US to republican Harry Boland. He gave them to his mother for safekeeping at her Dublin home.
She kept them after he was killed in the civil war and eventually handed them over to De Valera's government in 1938. The jewels were finally handed back to the Russian government in 1950 in return for the repayment of the $25,000 loan.