Zeki Celik has become Jose Mourinho's third signing of the transfer window at Roma, joining from Lille for a reported €7million fee.
Celik, who has signed a four-year contract with the Serie A club, was said to be of interest to Mourinho when he was Tottenham coach.
He follows midfielder Nemanja Matic and goalkeeper Mile Svilar – both of whom were free transfers – to Rome.
"For me, it is an honour to play for such an important club," Celik said. "I have great ambitions and I want to contribute to the success of the team.
"I feel ready and focused. I never give up, and you will always see me fighting on the pitch."
Celik spent four seasons at Lille, winning the Ligue 1 title in 2020-21.
However, that successful team has been broken up over the past 12 months, with Mike Maignan, Boubakary Soumare, Jonathan Ikone, Sven Botman and now Celik all moved on.
Renato Sanches is thought to be a transfer target for both Paris Saint-Germain and Milan.