Mr Fini and his wife Daniela arrived in London this morning accompanying Italy's president, Carlo Azeglio Ciampi, on a three-day state visit.
The couple sparked a bitter row in Italy over a pledge by Ms Fini and two Northern Alliance MPs to raise money to pay the €10,000 (£7,000) fine imposed on the former West Ham player Paulo Di Canio.
Di Canio, who now plays for the Serie A club Lazio, caused outrage when he gave a straight-arm salute to the club's notoriously rightwing fans after their 3-1 win over rivals Roma on January 6.
Today dozens of anti-fascist protesters lined the Mall today as Mr Fini and his wife were taken by open-top horse-drawn carriage to Buckingham Palace to meet the Queen.
"He waved at us and managed to hold himself back from his normal salute," said the joint secretary of Unite Against Fascism, Weymouth Bennett. "It is a very dangerous precedent that someone like him, who has swapped his black shirt for an Armani suit, should be able to claim respectability by meeting the Queen."
Palace officials admitted the Queen would have shaken hands with Mr Fini when the Italian party was introduced to the monarch at Buckingham Palace.
"He is here in his official capacity as foreign minister and the Queen is effectively looking after the guests of the Italian president," a palace spokesman said.
He added that visits of heads of state were proposed by the government not the royal household. Although officials would not confirm the guest list, Mr Fini and his wife were expected to attend a state banquet at Buckingham Palace this evening.
The row over Di Canio's salute and the payment of his fine has been a setback for the National Alliance in its bid to ditch its fascist heritage.
Ms Fini said the collection for the player would be "an act of solidarity". She complained that leftwing players and supporters had been given less harsh penalties for political gestures and added: "If politics has no place in the stadium, then it should have no place there for anyone."
The Alliance, the second biggest party in Silvio Berlusconi's rightwing coalition, grew out of the Italian Social Movement, which was founded after the second world war to perpetuate the ideas of Italy's former dictator, Benito Mussolini, and his black-shirted supporters.
In an effort to become more mainstream, Mr Fini has publicly condemned Mussolini and distanced himself from his granddaughter, Alessandra Mussolini, founder of the far-right Social Alternative movement. Ms Mussolini went on hunger strike yesterday to protest against being banned from next month's regional elections.
