The 30-year-old signed a four-year deal with the Spanish champions after a successful period in the Italian League.
Juventus helped win three league titles during his four years at the club and it seems that he will add another season this season with four clear points for the team at the top of the table.
Veteran duo contracts
Bosnian international move will see Arthur move from Barcelona in the other direction, as Juventus paid 80 million dollars to the Brazilian.
Arthur joined Barcelona from Brazilian club Gremio in 2018, winning the league title and Super Cup in his first season.
Like Pjanic, the 23-year-old will not move to his new club until the end of the season.
Juventus also agreed to extend a one-year contract for both the 35-year-old captain Giorgio Chiellini and 42-year-old goalkeeper Gianluigi Buffon.
The veteran goalkeeper has played more than 500 times with Juventus since his debut in 2001 and returned to the Italian team last year after an important period with French champion PSG.