The Serie A powerhouse have chosen previous Italy boss the veteran manager to lead the team for the remainder of the campaign.
The experienced coach steps in for the Croatian manager, who was dismissed post the Lazio setback last weekend.
Tudor arrived at the club in March to replace Thiago Motta but departed after seven months after an eight-game winless streak.
Spalletti guided Napoli to the Serie A crown in 2022-23 then moving on to lead the Italian national team, after the team's failure to reach the 2022 World Cup during Roberto Mancini's tenure.
Under his guidance, they made it to Euro 2024 exiting in the last 16 stage against Switzerland.
However, Spalletti was sacked by Italy 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 secured two Russian Premier League titles with Zenit St Petersburg.
Juventus were temporarily led by Massimo Brambilla for their 3-1 win against Udinese on Wednesday moving them to seventh position in the league - 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.
