Chelsea have officially completed the signing of 19-year-old French defender Mamadou Sarr from Ligue 1 club RC Strasbourg for a reported fee of £12 million.
Mamadou Sarr has penned an eight-year contract that will keep him at Stamford Bridge until 2033.
Sarr becomes the first player to move between Chelsea and Strasbourg since both clubs came under the ownership of Todd Boehly and Clearlake Capital through their BlueCo consortium.
The transfer was initially agreed in January and finalized this summer following Sarr’s impressive season in France.
The France Under-20 international made 28 appearances across all competitions for Strasbourg during the 2024-2025 campaign, playing a pivotal role in helping the club secure a seventh-place finish in Ligue 1 and a spot in the UEFA Conference League play-offs.
Known for his composure on the ball and defensive awareness, Sarr emerged from the youth systems of RC Lens and Lyon, making his senior debut for the latter in the 2022-2023 season.
He also spent a short loan stint with Belgian side RWD Molenbeek before joining Strasbourg last August, where he quickly became a defensive mainstay with 27 starts in Ligue 1.
Chelsea confirmed the signing in a statement, expressing delight at acquiring the promising centre-back.
“Chelsea is delighted to confirm the transfer of Mamadou Sarr from Ligue 1 side RC Strasbourg, with the defender signing a contract until 2033,” the club said.
Sarr is eligible to feature for Enzo Maresca’s side at the FIFA Club World Cup in the United States later this month.
Chelsea begin their campaign against Major League Soccer champions LAFC on June 16, followed by group matches against Flamengo on June 20 and ES Tunis on June 25.
His arrival marks Chelsea’s fourth signing of the summer transfer window, following deals for Liam Delap (£30m from Ipswich Town), Estevão (£29m from Palmeiras), and Dario Essugo (£18m from Sporting Lisbon).
