Can only moved to the Signal Iduna Park on the final day of the January transfer window on a deal until the end of the season with Dortmund having the option to make the move permanent.
The 26-year-old German international has impressed in his four games so far for Dortmund, scoring a 30-yard wonder strike against Bayer Leverkusen on his Bundesliga debut.
Can has signed a four-year contract until the summer of 2024 with Dortmund forking out £21m for his services.
"Bundesliga club Borussia Dortmund have reached an agreement with Italian record champions Juventus over the permanent transfer of Germany international Emre Can," read a statement on Dortmund's website.
"The 26-year-old's loan deal ends in June. As of 1 July, a valid contract between Borussia Dortmund and Can will enter into force and run until 30 June 2024."
Can moved to Juventus on a free transfer from Liverpool in the summer of 2018, winning a league and cup double under Massimiliano Allegri in his first season in Turin.
A change of management at the start of this season saw Maurizio Sarri take over from Allegri, and Can fell down the pecking order when Aaron Ramsey and Adrien Rabiot joined Juventus on free transfers.
Can made just eight appearances for Juventus in the first half of this season and was excluded from the club’s UEFA Champions League squad.