
The 28-year-old has won back-to-back Serie A and Coppa Italia doubles since joining the Bianconeri from Roma in 2016.
Known as a set-piece specialist, Pjanić has scored 15 league goals directly from free-kicks since arriving in Italy in 2011.
“I’m very happy to extend my contract until 2023 with this amazing club,” Pjanic, who has scored 12 goals in 79 international appearances for Bosnia, wrote on Twitter.
Juve kicked off their Serie A title defence last Saturday with a dramatic 3-2 victory at Chievo as Portuguese great Cristiano Ronaldo made his competitive debut after joining from Real Madrid for 100 million euros (RM470 million) last month.