Fagioli's previous deal, signed in August 2022, was valid until 2026.
"The relationship with Nicolo therefore continues, with the midfielder having arrived at Juventus in 2015 as a 14-year-old, rising through the youth ranks until his senior debut in 2021," Juventus said in a statement.
Fagioli's ban, who made his Italy debut in a friendly 3-1 win against Albania in November 2022, began on October 19, meaning the player could return to the squad for the end of the season.