Billy Gilmour was born on 11 June 2001 in Glasgow, Scotland, and came through the youth ranks at Rangers before Chelsea won the race for his signature in May 2017, beating out interest from several of Europe's biggest clubs in a move reported at around £500,000.
He broke into Chelsea's first team during the 2019–20 season, making his Premier League debut against Sheffield United in August 2019. A standout FA Cup fifth-round performance against Liverpool in March 2020 announced him to a wider audience and helped establish his reputation as a composed, precise passer with a natural feel for controlling the tempo of a game.
Gilmour was part of the Chelsea squad that won the UEFA Champions League in 2020–21. He spent the 2021–22 season on loan at Norwich City before joining Brighton on a permanent five-year deal in September 2022 for a reported fee of up to £16 million. In August 2024 he moved to Napoli in Serie A on another five-year contract, where he won the Serie A title in 2024–25.
On the international stage, Gilmour has represented Scotland at multiple youth levels from 2015 onward. He made his senior debut for Scotland in a friendly against the Netherlands in June 2020 and scored his first international goal against France in October 2023. He was selected for UEFA Euro 2024, adding to his growing collection of senior caps.
Chelsea, where his professional journey began, remains a significant chapter in shaping the technically gifted midfielder he is today.