The 21-year-old centre-back has signed a five-year contract with the Premier League side.
Crystal Palace have confirmed the signing of Marc Guehi from Chelsea.
The defender has signed a five-year deal with the Eagles, joining in a deal believed to be around £20 million ($28m).
The 21-year-old came through the Chelsea youth ranks after joining the club in 2007 but made just two senior appearances for the club before making the permanent switch to Selhurst Park.
