The Italian champions have the option to sign the Danish striker at the end of his spell and the 24-year-old is looking forward to his time playing in Serie A.
"I want to fulfil my potential here and show the fans my absolute best as that is yet to come. I am sure I will," he wrote on Twitter.
Bendtner spent last season on loan at Sunderland where he scored eight goals in 25 starts after he struggled to break into the first team at Arsenal.
Juventus had been linked with moves for Marco Borriello, Dimitar Berbatov and Fernando Llorente.
Bendtner will be competing with the likes of Mirko Vucinic for a starting spot at the Juventus Stadium.