Andrea Pirlo, 41, replaces Maurizio Sarri who was sacked after just one season as Juventus crashed out of the Champions League in the last 16.
Juventus sacked coach Maurizio Sarri on Saturday, less than 24 hours after Italian champions crashed out of Champions League after losing to French side Lyon over two legs in last 16.
Lyon coach Rudi Garcia hailed his team for seeing off Juventus and the "extraterrestial" Cristiano Ronaldo to reach the Champions League quarter-finals on Friday.
Champions League: Juventus, who won their ninth Serie A title in a row, trail the Ligue 1 side following their 1-0 defeat in France six months ago before the coronavirus lockdown.
UEFA Champions League and Europa League resume this week after being frozen in March as the coronavirus pandemic took hold across the continent.
Ciro Immobile scored in Lazio's final game of the season to match Argentina forward Gonzalo Higuain's record of 36 goals, set while playing for Napoli in the 2015-16 season.
It was Juventus's second consecutive defeat since sealing a ninth Serie A title in a row, just days before their Champions League campaign resumes against Lyon.
From Lionel Messi, to Cristiano Ronaldo, Mohamed Salah, Robert Lewandowski and Erling Braut Haaland, nobody in Europe has managed to keep pace with Lazio's Ciro Immobile.
Barcelona have demanded that Arthur Melo returns to training as he is under contract till the end of the season.
Football legend Pele took to social media to congratulate Juventus on winning the Serie A title, and he had special praise for striker Cristiano Ronaldo.
Juventus on Monday confirmed that Paulo Dybala suffered a thigh injury in their match against Sampdoria on Sunday.
Maurizio Sarri, whose only previous trophy was the Europa League last year with Chelsea, guided Juventus to their ninth straight Serie A title.
Cristiano Ronaldo opened the scoring deep into first half stoppage time in Turin and then had a hand in Federico Bernardeschi netting the second after 66 minutes.
Inter Milan manager Antonio Conte has brushed aside speculation that the club want to sign Lionel Messi to rival Juventus star Cristiano Ronaldo.
Inter Milan pulled back ahead of Atalanta, and within four points of leaders Juventus, who are poised to claim a 36th 'Scudetto' when they play Sampdoria.
Juventus need just three more points and the coronation could even come on Saturday, depending on the results of their rivals Atalanta and Inter Milan.
Juventus ended a three-match winless run thanks to Cristiano Ronaldo's second-half brace that moves them eight points clear of second-placed Inter Milan with four games remaining.
Romelu Lukaku's penalty two minutes from time rescued a point for Antonio Conte's Inter Milan, who are second, five points behind Juventus.