Òscar Mingueza was born on May 13, 1999 in Santa Perpètua de Mogoda, a municipality in Vallès Occidental. The central defender has dressed as a Barça player all his life, from Prebenjamín to Barça B. With the Barça B team, he made his debut on July 27, 2016, in a friendly match against Llagostera. But until the 2018/19 season, he has not become part of the subsidiary.

His last campaign in Juvenil A was 2017/18. A fruitful course for Mingueza since his contributed defensive solidity served to lift the Youth League and the League.

In the 2018/19 season, he participated in 15 games, 11 as a starter, adding 959 minutes of experience in the category. He also featured in five UEFA Youth League matches for Juvenil A. In the 2019/20 season, he played 16 league games and three in the promotion play-off. He has a contract until June 30, 2021.

Mingueza made his debut with the first team on November 24, 2020, in a Champions League group match against Dinamo Kyiv, where Barça won 0-4. He assisted a goal, specifically the 0-2, to Braithwaite.

From that moment on, the Catalan defender progressively added minutes until he became an important man in the rotation of the Barça defense. On April 30, 2021, after a season with a leading role in which he played 39 games (27 in the League, five in the Champions League, five in the Copa del Rey, and two in the Spanish Super Cup), Òscar Mingueza signed the extension of his contract until the summer of 2023, which made him a first-team player for all purposes.