The 19-year-old Romanian central defender had been linked with a host of clubs, including Borussia Dortmund and Newcastle United, but has committed to Juventus until the end of the 2024-25 season.
Dragusin, who is 6ft 3in tall, has been compared in his style of play to Liverpool's Virgil van Dijk and has previously highlighted the Dutchman as a player he admires.
Juventus acquired him from Romanian club Regal Sport in 2018, and this season saw Dragusin make his first-team debut in December against Dynamo Kiev in the Champions League.
His new deal was announced on the Juventus website on Friday, with the club stating: "Dragusin's journey continues with Juve. Congratulations, Radu! See you on the pitch!"