Italiano, who announced his resignation as Fiorentina boss on Sunday after their final game of the season, has signed a two-year contract with Bologna, replacing Motta who did not renew his contract at the end of the season.
He joined Fiorentina in 2021 having managed Spezia who he guided to promotion to Serie A. He took Fiorentina back to European football after a five-year absence in his first season in charge and led them to three cup finals.
Last season ended in another disappointment, however, as Italiano's side lost the Europa Conference League final for the second successive season.
He will get his first taste of managing a team in the Champions League at Bologna, who finished fifth in Serie A under Motta to qualify for Europe's most prestigious club competition for the first time.
Motta is expected to take charge of Juventus, Italian media reported, in replace of Massimiliano Allegri who was sacked.