The 25-year-old has penned a five-year contract with the club, for a reported fee of €7m (£5.53m).
Bonaventura has been capped once by the Italian national side and scored eight goals in Serie A last season.
He has become the club's third signing of the week, following the arrivals of Fernando Torres and Marco van Ginkel on loan from Chelsea.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Napoli | 23 | 17 | 3 | 3 | 38 | 16 | 22 | 54 |
| 2 | Inter Milan | 22 | 15 | 6 | 1 | 56 | 19 | 37 | 51 |
| 3 | Atalanta BCAtalanta | 23 | 14 | 5 | 4 | 49 | 26 | 23 | 47 |
| 4 | Lazio | 23 | 13 | 3 | 7 | 40 | 31 | 9 | 42 |
| 5 | Juventus | 23 | 9 | 13 | 1 | 39 | 20 | 19 | 40 |
| 6 | Fiorentina | 22 | 11 | 6 | 5 | 37 | 23 | 14 | 39 |
| 7 | Bologna | 22 | 9 | 10 | 3 | 35 | 27 | 8 | 37 |
| 8 | AC Milan | 22 | 9 | 8 | 5 | 33 | 24 | 9 | 35 |
| 9 | Roma | 23 | 8 | 7 | 8 | 34 | 29 | 5 | 31 |
| 10 | Udinese | 23 | 8 | 5 | 10 | 28 | 36 | -8 | 29 |
| 11 | Torino | 23 | 6 | 9 | 8 | 24 | 27 | -3 | 27 |
| 12 | Genoa | 23 | 6 | 8 | 9 | 21 | 32 | -11 | 26 |
| 13 | Hellas VeronaHellas Verona | 23 | 7 | 2 | 14 | 26 | 48 | -22 | 23 |
| 14 | Lecce | 23 | 6 | 5 | 12 | 18 | 41 | -23 | 23 |
| 15 | Como | 23 | 5 | 7 | 11 | 27 | 38 | -11 | 22 |
| 16 | Empoli | 23 | 4 | 9 | 10 | 22 | 33 | -11 | 21 |
| 17 | CagliariCagliari | 23 | 5 | 6 | 12 | 24 | 38 | -14 | 21 |
| 18 | Parma | 23 | 4 | 8 | 11 | 29 | 42 | -13 | 20 |
| 19 | VeneziaVenezia | 23 | 3 | 7 | 13 | 22 | 38 | -16 | 16 |
| 20 | Monza | 23 | 2 | 7 | 14 | 20 | 34 | -14 | 13 |
| > Serie A Full Table | |||||||||
