Juventus have chosen ex- Italian national team manager the veteran manager to lead the team for the rest of the term.
The experienced coach replaces his predecessor, who was dismissed following the loss to Lazio recently.
Tudor arrived at the club in March filling the shoes of Thiago Motta 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, which missed out on the 2022 World Cup during Roberto Mancini's tenure.
He secured their spot in Euro 2024 exiting in the last 16 stage against Switzerland.
Nonetheless, Italy dismissed Spalletti in June post a qualifying defeat against Norway, as Italy faced the possibility of not making a third World Cup in a row.
Spalletti's managerial career includes Inter Milan, Roma, and Udinese in Serie A and lifted the Russian league trophy twice while at Zenit St Petersburg.
Juventus were temporarily led by Massimo Brambilla for their 3-1 win against Udinese on Wednesday placing them seventh in the Serie A standings - six points adrift of Napoli at the top after nine rounds.
In the Champions League, they sit 25th in the league phase, after recording one defeat and two ties in the initial three fixtures.
