The ex-Crystal Palace player was a team-mate of City boss Roberto Mancini during their days together at Sampdoria.
The 44-year-old, who worked with Sampdoria's youth set up and then had a spell in charge of Swiss side FC Chiasso since retiring as a player, is the second addition to Mancini's backroom staff this summer following the arrival of David Platt.
He has already begun work with the team on tour in the United States.
"It is great that Attillio has come to join us," said Mancini on the club's website.
"He was a top class player and he will bring lots of experience and a winning mentality to the group. I know he is excited at being at Manchester City and I know that he loves the English game from his time in London."
Source: PA
Source: PA