Ansu Fati has extended his contract with Barcelona until 2027, the club announced on Wednesday, shortly after their 1-0 victory over Dynamo Kiev in the Champions League.
Fati, who has recently returned after almost a year out with a knee injury, will have a release clause in his new deal set at one billion euros.
"FC Barcelona and the player Ansu Fati have reached an agreement to renew his contract until 30 June 2027. The buy-out clause is set at 1 billion euros," a club statement read.
Fati, along with Spanish midfielder Pedri, is widely regarded as the most exciting talent in an emerging group of Barcelona youngsters.
The club's statement described Fati as "currently one of football's hottest properties" and "one of the squad's players with the brightest future".
After losing Lionel Messi to Paris Saint-Germain in the summer, the 18-year-old has taken the Argentinian's iconic number 10 shirt at Barca and his return from injury has lifted the mood in recent weeks.
He marked his comeback with a goal against Levante last month and scored his second of the season against Valencia on Sunday.
The teenager, who turns 19 on October 31, is still being eased back to full fitness and began on the bench against Dynamo on Wednesday, presumably with a view to starting in the Clasico against Real Madrid at Camp Nou this weekend.
Born in Bissau, Fati joined La Masia in 2012 and made his debut for the first team in 2019, aged 16.
The forward has broken a series of records, including becoming the youngest ever Barcelona player to score in La Liga, score at Camp Nou and play in the Champions League.
Fati scored his first Champions League goal against Inter Milan aged 17, breaking a tournament record that had stood since 1997.
In total, he has made 47 appearances for Barcelona, scoring 15 goals.