The Italian side fired Maurizio Sarri following their Champions League last-16 exit against Lyon on Friday, despite the former Chelsea boss having delivered the Serie A title.
Ex-Tottenham boss Mauricio Pochettino was the early favourite to land the role, but reports in Italy quickly emerged making it clear Pirlo was in line to step in.
The 41-year-old was only named as the new boss of Juventus’ U23 side, who play in Serie C, last month and had not yet managed a game prior to being promoted. He has no previous managerial experience.
As a player, however, he won four successive Serie A titles with the club between 2011 and 2015, having arrived on a free transfer from AC Milan, with whom he had won two league titles and the Champions League twice.
He was also part of the Italy side that won the 2006 World Cup and finished as runners-up at Euro 2012. He retired from playing in 2017, having seen out the final years of his career in MLS with New York City FC.