Mohamed Salah has completed his transfer from Basel to Chelsea for a reported £11m fee.
The 21-year-old, who becomes the first Egyptian to join the Blues, has signed a five-and-a-half-year contract.
"I'm very happy to sign for Chelsea, such a big club in the world," Salah, who also attracted interest from Liverpool this month, told the club's official website.
"I hope I can make the Chelsea supporters happy and have a good career at the club for many years to come."
The attacking midfielder, who scored in both Champions League games against Chelsea for Basel this season, will wear the number 15 shirt.
Germany
Switzerland
Hungary
Scotland
Spain
Italy
Croatia
Albania
England
Denmark
Slovenia
Serbia
Austria
France
Netherlands
Poland
Romania
Belgium
Slovakia
Ukraine
Portugal
Turkey
Georgia
Czech Republic