Youth years A
goalkeeper, Cox began his career in the
Chelsea Academy at age eight and concerns over his height led to his release at age 14. He moved into the
AFC Wimbledon academy and progressed to sign his first professional contract in on his 17th birthday in May 2020. Cox was an unused substitute with the first team on 18 occasions during the
2020–21 season. At youth level, Cox was a part of the Dons' 2020–21
EFL Youth Alliance Cup-winning squad (scoring two goals during the campaign) and he was recognised for his football and academic progress by the LFE in November 2020. Cox departed
Plough Lane in July 2021.
Brentford 2021–22 season On 22 July 2021, Cox transferred to the
B team at
Premier League club
Brentford and signed three-year contract, with the option of a further year, for an undisclosed fee. As a result of a long-term injury suffered by first-choice goalkeeper
David Raya in October 2021, Cox was promoted onto the first team substitutes' bench as backup for
loanee Álvaro Fernández. Cox dropped back out of the matchday squad, He made 18 B team appearances during the 2021–22 season. ankle injuries suffered by Strakosha during the season saw Cox serve as Raya's backup for 24 matches. He also made seven appearances during the B team's
2022–23 Premier League Cup-winning campaign. He began the season as first-choice goalkeeper, but following a dip in form, he was dropped in favour of
Jed Ward in late January 2024. Cox made just one further appearance before the end of the season and finished a mid-table campaign on 34 appearances.
2024–25 season and loan to Crawley Town During the first half of the
2024–25 season, Cox served as third-choice goalkeeper behind
Mark Flekken and
Hákon Valdimarsson and was an unused substitute during two
EFL Cup matches. On 28 January 2025, he joined League One club
Crawley Town on loan until the end of the
2024–25 season. Cox went straight into the
starting lineup and suffered a torn hamstring during his third appearance, which necessitated his return to Brentford for treatment. He did not appear again before the end of the League One season,
2025–26 season and loan to Shrewsbury Town Behind new signing
Caoimhín Kelleher and Hákon Valdimarsson in the pecking order, Cox failed to win a call into a matchday squad during the first half of the
2025–26 season. Cox made 18 appearances during his spell and was voted the club's Young Player of the Year. == International career ==