The renewal is the fourth continuity move announced by sporting director Fernando Soriano's department in two weeks, following extensions for Diego Villares, Adrià Altimira and goalkeeper Germán Parreño.
The club confirmed the deal via social media, describing Bil as embodying "talent, work, ambition and commitment" and calling him one of the great gems of the club's academy system.
Bil, born in Yaoundé on September 21, 2004, joined Deportivo's reserve side, Fabril, for the 2024-25 season and had a solid debut campaign with 31 appearances and five goals. The explosion came this season: he began 2025-26 with Fabril, scoring 12 goals and adding an assist in just 20 matches, form that earned him a senior debut in the Copa del Rey against Sabadell on December 4.
From that point, there was no looking back. Under head coach Antonio Hidalgo, Bil made 17 league appearances for the first team, scoring six goals and adding an assist, plus three cup appearances. His two goals in a 2-0 win over Real Valladolid at the Estadio José Zorrilla secured Deportivo's return to LaLiga for the first time in eight years.
Soriano had flagged the move as a priority weeks earlier, speaking to the SER radio network after the season's conclusion.
"It's a situation that has already been more than discussed, he deserves it. He will be a first-team player next season."
Head coach Hidalgo had also been effusive about the striker's impact before the season ended.
"He gives us a lot, an energy that is hugely important for us. Anything I could have imagined with him exceeds expectations, I'm absolutely delighted."
The renewal makes Bil, at 21, the only striker in Deportivo's squad with his place in next season's top-flight squad fully guaranteed. Soriano has described the club's transfer approach for the coming window as "a summer of signings in dribs and drabs" — prioritising the retention of the existing core before turning to the market.
For a player who trained with the first team during pre-season last year without anyone at the club anticipating the trajectory that would follow, a four-year contract represents Deportivo's clearest possible statement: whatever incomings arrive this summer, the forward line's foundation has already been decided.