Juventus have appointed former Azzurri manager the veteran manager as their manager for the rest of the term.
Spalletti takes over from his predecessor, who was let go post the Lazio setback last weekend.
Tudor arrived at the club in March filling the shoes of 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 then moving on to lead the Italian national team, 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.
Yet, the Italian FA let Spalletti go 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 lifted the Russian league trophy twice while at Zenit St Petersburg.
Massimo Brambilla took interim charge of Juventus in the midweek 3-1 triumph over Udinese which left them seventh in Serie A - 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.
