The Old Lady have appointed ex- Italy boss Luciano Spalletti to take the helm for the rest of the term.
The experienced coach takes over from his predecessor, who was sacked following the loss to Lazio recently.
The former boss came on board in March as Thiago Motta's replacement but exited following a seven-month stint at the end of an eight-match winless run.
Spalletti guided Napoli to the Serie A crown in 2022-23 before taking charge of Italy, who had failed to qualify for the 2022 World Cup with Mancini at the helm.
He helped them qualify for Euro 2024 exiting in the last 16 stage against Switzerland.
Nonetheless, Italy dismissed Spalletti in June after a World Cup qualifying defeat by Norway, with the Azzurri at risk of missing out on a third consecutive World Cup.
Spalletti's managerial career includes Inter Milan, Roma, and Udinese in Serie A and won the Russian Premier League twice with Zenit St Petersburg.
Massimo Brambilla took interim charge of Juventus during the 3-1 victory over Udinese on Wednesday which left them seventh in Serie A - six points behind leaders Napoli after nine games.
Their Champions League campaign sees them in 25th place in the group stage, with one loss and two draws in their first three games.