Liverpool Koumetio moved to
Liverpool's Academy from French side
US Orléans in November 2018. Koumetio was originally on the books of his hometown club
Olympique Lyonnais where he was predominantly a winger at first. His height led to coaching staff turning him into a centre-back when he was 14. Koumetio signed his first professional contract with Liverpool in August 2020, when aged 17 and already . He was a ball boy at
Anfield for the 4–0 semi-final second leg victory over
FC Barcelona in the
2018–19 UEFA Champions League in May 2019. In October 2019 he was named on the bench at the age of 16 for the
Carabao Cup tie against
Arsenal FC at Anfield. Koumetio featured for Liverpool during the pre-season of the 2020–21 football season in friendly matches in Austria against
Red Bull Salzburg and
VfB Stuttgart. Koumetio made his first-ever appearance for the Reds’ first team on 9 December 2020 substituting in for
Fabinho at the heart of defence in the
UEFA Champions League against
FC Midtjylland. In doing so, he became the youngest player to feature for Liverpool in the Champions League, a record that was later broken by
Stefan Bajcetic in 2022.
Austria Wien (loan) On 23 June 2022, Koumetio signed for
Austrian Bundesliga side
Austria Wien on a season-long loan. He was recalled on 10 January 2023.
Dunkerque (loan) On 29 August 2023, Koumetio joined
Ligue 2 side
USL Dunkerque on a season-long loan. He made his debut in a league fixture against
Grenoble Foot 38 on 16 September, and was sent off after 52 minutes for two bookable offences. He was recalled on 16 January 2024.
Blackburn Rovers (loan) On 1 February 2024, Koumetio joined
Blackburn Rovers on loan until the end of the season. He made his debut on 27 February as a substitute in an
FA Cup match against
Newcastle United.
Dundee On 9 August 2024, Koumetio left Liverpool and joined
Scottish Premiership club
Dundee on a two-year deal. He made his debut from the bench the following day in a league victory at home to
Heart of Midlothian. After suffering an ankle injury in December 2024 against
St Mirren, Koumetio spent several months recovering and returned as a substitute on 5 April 2025 against the same opponents in a home win. On 22 July 2025, Koumetio scored his first senior goal in an away win for Dundee against
Bonnyrigg Rose in the League Cup. ==International career==