The Old Lady have apparently agreed a short-term contract with the new manager until the end of the season, with the option of an extension in the event of Champions League qualification.
Juventus, after a successful start to the season, stretched their winless streak to eight competitive games with a defeat at Lazio at the weekend, which led the club's management to make a change at the helm.
The Bianconeri are currently down in eighth in Serie A, but are only three points behind fourth-placed Inter.
According to Gazzetta dello Sport, Spalletti has agreed to a short-term contract which runs until the summer. However, if Juventus qualify for the Champions League, the contract will be automatically extended.
"Me, the new coach of Juventus? So far I have not been in contact with any Italian teams, but I want to return," Spalletti said in an interview with Italian TV channel Sky Sport.
"Igor is a real man with values. You have to get on well with someone like him. He is a man with substance who gets straight to the point. Whoever replaces him on the Juventus bench will be lucky, he will definitely take over a well-coached team."
Spalletti last managed Napoli at club level, with whom he celebrated the scudetto in the 2022/23 season before an unsuccessful spell in charge of the Italian national team.
He has previously had long stints at Roma and Zenit St Petersburg, and has also coached Inter Milan, Empoli, Sampdoria and Udinese.