Barcelona have announced Gavi is now registered with the LaLiga.
The teen's new contract has been confirmed and he has also been handed a new number.
Gavi will wear the No6 and be secured to Barca by a deal to 2026. The agreement carries a 1bn buyout clause.
Barca had been blocked from registering Gavi by LaLiga due to Financial Fair Play issues, which saw him play out the season on a youth team.
But with room now made in the wage budget, Gavi has been confirmed as senior player and on a senior contract.