James Scanlon was born on 28 September 2006 in the Midlands, England, and developed as a footballer through the Derby County academy before joining Manchester United in February 2021. He progressed steadily through United's youth ranks, earning his first professional contract in May 2024 and travelling with the senior squad on their pre-season tour of the United States that summer.
A right-footed attacking midfielder who operates primarily on the left wing, Scanlon caught the eye during the 2023–24 season by featuring in Manchester United's UEFA Youth League campaign and training under first-team manager Erik ten Hag. He was named in a senior matchday squad for the first time in March 2025, for a UEFA Europa League tie against Real Sociedad. In February 2026, he joined EFL League Two side Swindon Town on loan for the remainder of the 2025–26 season, gaining his first regular senior experience.
On the international stage, Scanlon represents Gibraltar through his Gibraltarian mother. He made his senior debut as a substitute on 21 March 2024 in a Nations League play-out against Lithuania. On 8 September 2024, he scored his first senior international goal in a 2–2 draw with Liechtenstein, which made him the youngest goalscorer in UEFA Nations League history at 17 years and 346 days, surpassing the record previously held by Tjay De Barr. He also became the first Manchester United player to represent Gibraltar while registered at the club.