The defender, born in Zaandam on 1 February 2000, becomes the first official addition to Carlos Corberan's squad for the 2026-27 season. Valencia had already agreed the deal in January, as first reported by MARCA, information later confirmed by football CEO Ron Gourlay once the winter window had closed.
The club had tried to sign De Haas at that point but could not reach an agreement with Famalicao over a fee, with the defender still six months from the end of his contract. The move was instead left in place to be made official on 1 July.
De Haas arrives at Mestalla after three seasons in Portuguese football, during which he established himself as a regular starter at Famalicao. He featured in 33 league matches in the 2025-26 campaign, starting and completing every one of them, while also contributing six goals from centre-back.
Famalicao finished that season in fifth place in the Portuguese top flight. Standing at 1.94 metres and left-footed, De Haas is known for his ability to play the ball out from defence and for his authority in the air, according to Valencia's official statement announcing the signing.
He came through the youth ranks at AZ Alkmaar and PSV Eindhoven, and also spent time at Dinamo Zagreb before beginning his professional career at NK Lokomotiva Zagreb. It was from Croatia that he made the move into Portuguese football.
Beyond his club career, De Haas has represented the Netherlands at Under-16, Under-17 and Under-18 level.
His arrival gives Corberan an experienced left-footed option at centre-back as Valencia begin shaping their squad for next season.
The confirmation brings to an end a saga that stretched back to the turn of the year, when Valencia first moved to strike a deal for the defender only to find Famalicao unwilling to lower their asking price with De Haas still under contract.
Waiting for his deal to expire allowed Valencia to complete the transfer without paying a fee, even if it meant a six-month delay before the move could be made official. De Haas's route to Mestalla has taken in four countries, from his homeland through Croatia and on to Portugal, before this switch to LaLiga.
That background, combined with his height and left-footed profile, was highlighted by the club as a key factor behind the decision to pursue the deal.