Marcus Bettinelli was born on 24 May 1992 in Camberwell, Greater London, and began his footballing journey at Fulham's academy at the age of 14. After loan spells at Dartford and Accrington Stanley helped him build first-team experience in the lower leagues, he eventually established himself as Fulham's first-choice goalkeeper and played a key role in their 2018 EFL Championship play-off final win at Wembley, where Fulham defeated Aston Villa 1–0 to secure promotion to the Premier League.
A composed and reliable shot-stopper, Bettinelli joined Chelsea in the summer of 2021 on a two-year contract, taking on a backup role behind the club's first-choice keepers. During his time at Stamford Bridge he contributed to the squad that claimed the UEFA Conference League in 2024–25, as well as the FIFA Club World Cup in 2021, adding silverware to a career that had previously been defined more by consistency than trophies.
On the international stage, Bettinelli earned a call-up to the senior England squad in September 2018 for fixtures against Spain and Switzerland, having previously made one appearance for the England under-21 side in 2015.
In June 2025, Manchester City announced his signing on a one-year deal. At City he is expected to serve as a dependable backup option in a squad competing at the highest levels of English and European football.