Mancini, as had been widely predicted, was named as the new national team coach to replace the hapless Gian Piero Ventura, sacked in November after Italy missed out on the World Cup for the first time since 1958.
With the Italian football Federation 53-year-old has signed a two year contract.
Italian FA commissioner Roberto Fabbricini said Mancini has been chosen because he "had a great desire to sit on the Italy bench and he proved it in a concrete way".
Mancini left his job at Zenit St. Petersburg on Monday by mutual consent.
"Everything went as we wanted".
Mancini's first match in charge will be a friendly against Saudi Arabia on 28 May before Italy play France and Holland in June. As head coach Italian since 2001, has won 13 titles, including victories in Serie A and the English Premier League. He also won Italian Cups with Inter, Fiorentina and Lazio.
Since then Mancini has guided Galatasary to Turkish Cup glory before steadying the ship in his second stint at Inter Milan.
Like this, there are a lot of issues still to be addressed, and Roberto Mancini now has two years in which to rebuild Italy in order that they become a force to be reckoned with once again.
He reached the semi-finals of Euro 1988, and was in the squad that finished 3rd in the 1990 World Cup on home soil.