Juventus have appointed ex- Italian national team head coach Spalletti to lead the team until the end of the season.
Spalletti takes over from the Croatian manager, who was dismissed following the loss to Lazio recently.
Tudor arrived at the club in March as Thiago Motta's replacement but exited following a seven-month stint following a string of eight matches without a victory.
Spalletti led Napoli to the Serie A title in 2022-23 before taking charge of Italy, which missed out on the 2022 World Cup under former boss Roberto Mancini.
He secured their spot in Euro 2024 exiting in the last 16 stage against Switzerland.
Nonetheless, Italy dismissed Spalletti in June after a World Cup qualifying defeat by Norway, putting Italy in danger of missing a third straight World Cup.
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.
Massimo Brambilla served as interim manager for Juventus during the 3-1 victory over Udinese on Wednesday placing them seventh in the Serie A standings - six points behind leaders Napoli after nine games.
Their Champions League campaign sees them in 25th place in the group stage, having lost once and drawn twice in their opening three matches.