The midfielder was no longer needed by the Serie A champions, and will now try and get his career back on track with the Rossoblu
The Felsinei were keen to add some more experience to their squad before the closure of the transfer window, and head coach Stefano Pioli had made 30-year-old his primary transfer target.
The player was eager to leave the Turin giants after failing to secure regular first team football, and will now try to relaunch his career at Dall'Ara.
Pazienza, who moved to Turin in June 2011, made nine appearances for the Bianconeri before spending the second half of last season on loan at Udinese.
The midfielder previously wore the jerseys of clubs such as Foggia, Fiorentina and Napoli.
Bologna will present their latest signing at a press conference later on Thursday.