The Serie A powerhouse have appointed former Italian national team manager Spalletti to lead the team for the rest of the term.
The 66-year-old takes over from the Croatian manager, who was let go post the Lazio setback last weekend.
Tudor arrived at the club in March to replace Thiago Motta but exited following a seven-month stint after an eight-game winless streak.
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.
Under his guidance, they made it to Euro 2024 where they were knocked out in the last 16 by Switzerland.
However, Spalletti was sacked by Italy in June after a World Cup qualifying defeat by Norway, as Italy faced the possibility of not making a third World Cup in a row.
He has previously coached Inter Milan, Roma, and Udinese in Italy's top flight and secured two Russian Premier League titles with Zenit St Petersburg.
Massimo Brambilla took interim charge of Juventus during the 3-1 victory over Udinese on Wednesday 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, after recording one defeat and two ties in the initial three fixtures.