The tricky winger, who has been capped 14 times for Italy, joins for a fee of £6.5m, and is Sunderland's ninth signing of a window where new boss Di Canio has undertaken a complete overhaul of his squad. He joins other high-profile signings such as Jozy Altidore and Modibo Diakité, and is also the second Italian to join this window after Vito Mannone.
Giaccherini played for Juventus for two years after joining the club fresh from a breakthrough season at Cesena. Although he has spent most of his career at his first club and the national team as a winger, he was often played as a central attacking midfielder at Juventus. At Sunderland, his versatility should serve him well as he looks to play alongside the likes of Stephane Sessegnon and Adam Johnson behind the striker.