Allegri will have won the Serie A title in all five of his seasons with Juve - having done likewise in his first campaign with AC Milan in 2010-11 - while also lifting the Coppa Italia on four occasions.
But the 51-year-old's future at the Allianz Stadium had been uncertain ever since Juve crashed out of the Champions League at the hands of Ajax.
Following a meeting with president Andrea Agnelli this week, Allegri has decided to step down and seek a new challenge away from Turin.
Given his success in Italy, a number of teams - including some of those he has faced regularly in Serie A - could be interested. Here, we assess potential landing spots for Allegri.
Bayern Munich (current boss: Niko Kovac)
Bayern could be another side soon to be in the hunt for a new man at the helm as questions continue to be asked of Kovac. Despite being on course for a domestic double, with Bayern two points clear of Borussia Dortmund at the top of the Bundesliga with a game to go ahead of the DFB-Pokal final, Kovac reportedly does not fit the profile for the type of man the German giants are after - something which would not be a problem if Allegri is appointed.
Chelsea (current boss: Maurizio Sarri)
Sarri appears to be living on borrowed time at Stamford Bridge even if, like Kovac, he can reflect on a debut campaign at a new club with plenty of positives. He guided Chelsea to third in the Premier League, a Wembley appearance in the EFL Cup - they battled with Manchester City for 120 minutes before losing on penalties - and to the final of the Europa League, where domestic rivals Arsenal await on May 29. Should they turn to Allegri, he will become the seventh Italian coach to have managed the club in the past two decades.
Paris Saint-Germain (current boss: Thomas Tuchel)
Tuchel has been unable to shake off rumours that he will be on his way out following a solitary season in charge, not helped by his side's poor run of form towards the end of the campaign. PSG retained their Ligue 1 crown with plenty to spare, but they were unable to do likewise in the Coupe de France and Coupe de la Ligue, while they also exited the Champions League at the last-16 stage. As a two-time finalist in UEFA's showpiece club competition, PSG's ambitious owners may see Allegri as the right fit to at least take them beyond the quarter-finals - something they have failed to achieve under Qatari ownership.
AC Milan (current boss: Gennaro Gattuso)
Milan chief executive Ivan Gazidis is reportedly in the process of meeting candidates to take over from Gattuso, who has had his coaching credentials questioned in a season that has seen the fallen Italian giants struggle for consistency. With surprise package Atalanta three points better off in the race for the final Champions League qualifying spot, Milan face the prospect of another season away from European football's top table. Given his San Siro past, where he won the Serie A title and the Supercoppa Italiana, could Allegri be tempted by a return to Milan to help revive his former side's faltering fortunes?
Inter (current boss: Luciano Spalletti)
Allegri may take the controversial option of managing Milan's bitter rivals should he not fancy a return to the club he left in 2014 when sacked midway through the campaign. Lifting the Serie A title with a third different club may appeal to him, particularly as Inter are rumoured to be ready to spend big in the next transfer window as they aim to challenge for major honours once again. Spalletti is the man in charge at the Nerazzurri, but an underwhelming 2019 has seen his future called into question.
Arsenal (current boss: Unai Emery)
Perhaps the only one of the clubs listed where the top job is not under immediate threat, although Arsenal chiefs may opt to twist should they lose their huge Europa League final showdown with Chelsea. Allegri was tipped to succeed Arsene Wenger at Emirates Stadium last year, only for Emery to get the nod, and the Spaniard worked through a mixed campaign in the Premier League. The big question is, though, would Allegri be happy to join a club in need of improvements but without huge funds available to spend?