The Blues have signed attacking midfielder Kai Havertz from Bayer Leverkusen on a five-year contract in a deal worth about £71m which includes add-ons.
The Germany international has scored 36 goals and contributed 25 assists in 118 appearances for the Bundesliga club.
Havertz is Chelsea’s second most expensive signing after Kepa Arrizabalaga who arrived at the Stanford Bridge from Athletic Bilbao (£71.6m) in 2018.
“I am very happy and proud to be here. It is a dream come true to play in a big club like Chelsea,” said Havertz, according to the BBC.
Havertz, 21, is Blues manager Frank Lampard’s seventh signing of the summer.
Havertz scored 18 goals in 45 appearances last season, including eight in the 11 games after the campaign restarted.