The Old Lady have appointed previous Italian national team head coach Spalletti to take the helm for the remainder of the campaign.
The experienced coach steps in for his predecessor, who was dismissed post the Lazio setback recently.
Tudor had joined the club in March to replace Thiago Motta but departed after seven months after an eight-game winless streak.
Spalletti led Napoli to the Serie A title in 2022-23 before taking charge of Italy, who had failed to qualify for the 2022 World Cup with Mancini at the helm.
Under his guidance, they made it to Euro 2024 exiting in the last 16 stage against Switzerland.
Yet, the Italian FA let Spalletti go in June after a World Cup qualifying defeat by Norway, putting Italy in danger of missing a third straight World Cup.
Spalletti has also managed Inter Milan, Roma and Udinese in Serie A and secured two Russian Premier League titles with Zenit St Petersburg.
Massimo Brambilla served as interim manager for Juventus in the midweek 3-1 triumph over Udinese placing them seventh in the Serie A standings - trailing leaders Napoli by six points after nine matches.
In the Champions League, they sit 25th in the league phase, having lost once and drawn twice in their opening three matches.
