31-year-old Amauri found himself surplus to requirements at the Turin outfit following the club's decision to hand the coaching reins to former skipper Antonio Conte.
Having been linked to several outfits such as Roma and English side Tottenham Hotspur, Fiorentina sporting director Pantaleo Corvino announced last week that the club had struck an agreement with Juventus for the former Palermo frontman.
The Florence side declared the completion of the Amauri loan deal on its official website on Tuesday.
"Fiorentina announces that they have acquired from Juventus, on a temporary basis, the services of the forward Amauri Carvalho de Oliveira," a statement read.
Fiorentina had been looking to draft in attacking reinforcements after offloading striker Alberto Gilardino to Genoa in the current transfer window.
Amauri had netted 17 league goals in 71 appearances for Juventus following his big-money move from Palermo.