The Bianconeri moved quickly and quietly to get the deal over the line just as Çelik appeared close to renewing with the Giallorossi after lengthy talks, with the defender putting pen to paper on a contract running through 30 June 2029.
In their official statement, Juventus confirmed the club will bear accessory costs of €1m relating to Çelik's registration, payable over the course of the deal — reflecting the free-transfer nature of the move.
"Çelik arrives in Turin backed by significant experience gained, most recently, between France and Italy. After making his mark at home until 2018, he spent four seasons at Lille, where he helped the club win a French league title and a French Super Cup, standing out for his consistency and reliability," the club said in its presentation of the player.
Born in 1997, Çelik built his reputation in Ligue 1 before moving to Serie A, where he became a regular fixture at right-back for AS Roma across several seasons. His departure from the capital catches Roma off guard, given the club had been in advanced negotiations over an extension before Juventus swooped in to complete the deal within a matter of hours.
The move represents a rare piece of transfer-market opportunism between two Serie A rivals, with Juventus effectively securing a proven top-flight full-back without paying a transfer fee.
Speaking on Sky, pundit Aldo Serena offered a measured assessment of Juventus's new full-back.
"He's not a superstar, but he's a reliable and versatile player, someone you can always count on," Serena said, framing the signing as a smart, low-cost piece of business for a position that has needed depth.
With Çelik now in the fold, Juventus add proven Serie A experience and tactical versatility to their defensive options at minimal financial outlay, a deal that fits the profile of shrewd business the club have targeted so far this transfer window as they look to strengthen without breaking the bank.
The Turkish international's ability to operate as either a right-back or wing-back gives head coach Luciano Spalletti flexibility across different defensive systems, and his experience of Serie A football means no adaptation period should be required before he is ready to contribute.