The 19-year-old succeeds Paris Saint-Germain's Désiré Doué, becoming the latest Barcelona player to receive the prestigious award presented by Italian newspaper Tuttosport.
Cubarsí's achievement follows a remarkable season at club and international level, crowned by his role in Spain's 2026 World Cup triumph. He will collect the award at a ceremony in Turin on December 14.
The defender was selected following a vote by an international panel of journalists, with the announcement made at the MAPEI Football Center in Sassuolo. Former Italy international Demetrio Albertini attended as the event's special guest.
Cubarsí was chosen ahead of a strong group of emerging players, including Bayern Munich's Lennart Karl, Real Madrid's Yan Diomande and Paris Saint-Germain's Warren Zaïre-Emery.
Barcelona team-mate Lamine Yamal was not eligible to win again, having already claimed the award in 2024. Tuttosport's rules prevent a previous winner from receiving the prize for a second time.
The result continues Barcelona's remarkable connection with the award. Cubarsí becomes the club's latest winner after Lionel Messi, Pedri, Gavi and Yamal, while Spain has now produced six recipients in total.
Cesc Fàbregas was the first Spanish winner in 2006, followed by Isco Alarcón in 2012, Pedri in 2021, Gavi in 2022 and Yamal in 2024.
The 2026 award also represents another milestone for defenders. Cubarsí is only the second centre-back to win the Golden Boy since its introduction in 2003, following Matthijs de Ligt, who received the honour in 2018 while playing for Ajax.
His rise has been particularly impressive given how quickly he has established himself in Barcelona's first team.
Cubarsí made his senior debut under Xavi Hernández on January 18, 2024, starting the Copa del Rey match against Unionistas. He has since become an important part of the club's defence, accumulating 141 first-team appearances according to the supplied figures, alongside 23 appearances for Spain.
The departure of Iñigo Martínez increased the responsibility placed on the young defender, but Cubarsí responded with a level of maturity and authority that belied his age.
His ability to progress possession through accurate passing has become one of his defining qualities. He is comfortable stepping into midfield with the ball, but has also developed the defensive awareness to protect his penalty area and compete in demanding one-on-one situations.
Those qualities were particularly evident during Spain's World Cup campaign. Cubarsí played every available minute of the tournament, forming an effective central defensive partnership with Aymeric Laporte as Spain conceded just once.
His performances earned him the tournament's Best Young Player award, while one of his most important interventions came in the final against Argentina.
With the match approaching its conclusion, Cubarsí produced a crucial defensive intervention to cut out a Giuliano cross intended for Marcos Senesi, preventing Argentina from forcing the final into a penalty shootout.
He had already demonstrated his quality at club level, helping Barcelona win LaLiga and the Spanish Super Cup, but his performances on the international stage further strengthened his case for the Golden Boy.
Cubarsí's victory was part of a wider collection of awards announced at the event. Felicia Schröder of Real Madrid won the Golden Girl award, while Andrea Berta of Arsenal was named best executive and Joan Laporta received the best president award. Erling Haaland and Alessia Russo were recognised as Golden Player winners in the men's and women's categories respectively, while Jorge Mendes was named best agent. Honest Ahanor of Crystal Palace and Giulia Galli of Barcelona received the Italian Golden Boy and Golden Girl awards.
The result gives Barcelona another reason to celebrate its youth development system. Four of Spain's six Golden Boy winners have come through La Masia, with the other two being Fàbregas and Isco.
Cubarsí's award is particularly significant because it recognises a defender whose influence has been built on reading the game, positional intelligence and composure rather than goals and attacking statistics.
At 19, he has already won major honours with Barcelona and Spain, established himself internationally and become one of the most highly regarded young defenders in European football.