Demetri Mitchell joined Exeter City for an undisclosed fee from Hibernian in January 2023. He was one of six City signings in the January transfer window.

Demetri was a member of Manchester United academy teams from the age of ten becoming a scholar in 2013 and later signing professional. He made his first-team debut, as a starter, against Crystal Palace in the final league game of the season in May 2017. That was to be his only first-team appearance, and after two loan spells at Hearts, Demetri left Old Trafford for Blackpool in 2020. Whilst at Manchester United he had played for England at under-16 level through to under-20 and was part of the squad which won the 2014 European Under 17 Football Championship.

At Blackpool Demetri saw promotion to the Championship before signing for Hibernian for an undisclosed fee in January 2022. He was to spend almost exactly a year at Easter Road, making nine league appearances, before joining Exeter.

Demetri made his Exeter debut on 28 January 2023 as a substitute at MK Dons and scored his first City goal against Charlton Athletic on 4 February 2023. Moving into his first full season with the Grecians, he scored the winner when City beat Premier League Luton Town in the League Cup in September 2023. Then, after showing fine form over a number of games, Demetri suffered a serious knee injury against Middlesbrough in the next round of the League Cup.