Ismaila Sarr has left Rennes for Watford in a club-record deal, signing a five-year contract at Vicarage Road.
The Senegal international is reported to have cost the Hornets £32.3million (€35m).
Sarr has long been linked with a move to the Premier League with Watford, although with Wilfried Zaha's future uncertain, Crystal Palace were also said to be interested in the 21-year-old.
But Sarr, who scored eight goals in 35 Ligue 1 appearances last season, completed the switch to Watford ahead of the Premier League transfer deadline.
Are you happy to be here, @izosarr? pic.twitter.com/Ut4S6dIbSi
— Watford Football Club (@WatfordFC) August 8, 2019
Sarr, who played in the Africa Cup of Nations final, follows Danny Welbeck - the former Arsenal forward having signed on Wednesday - in making the move to Watford in this window.