The Bosnia and Herzegovina midfielder has spent the past two seasons with the Bianconeri and has agreed to stay until the end of the 2022/23 campaign.
Pjanic, 28, has helped Juve won the Serie A and Coppa Italia double in both of his seasons at the club following five productive but trophy-less years at Roma.
A statement on the club website read: “Juventus are delighted to announce that Miralem Pjanic has renewed his contract at the club until 2023.
“Since arriving prior to the 2016/17 season, Pjanic has become an increasingly-integral part of the Bianconeri midfield, providing pin-point passes across the pitch while firing free-kicks into the back of the net with outstanding consistency.”
