Scottish international midfielder Billy Gilmour joined Norwich on 2nd July 2021 on a season long loan from Chelsea.

Daniel Farke's close relationship with Blues boss Thomas Tuchel is thought to have played a significant role in convincing the Chelsea chief that City was the perfect destination for Gilmour to continue his development. City's boss worked alongside Tuchel at Borussia Dortmund and the pair share a similar outlook on football. Farke's tactical style and the progress Spurs youngster Oliver Skipp made on loan in Norfolk last year are also believed to be factors in the decision to send Gilmour to Norwich.

Raised in Scotland, he was part of Scottish Football Association's Performance School programme and joined Rangers. He was fast-tracked and made his debut for the under-20 development team in December 2016 at the age of 15. He was also included in the provisional squad for Scottish Cup matches by caretaker manager Graeme Murty. He turned down a professional contract with Rangers to join Chelsea in 2017 with Chelsea paying an initial development fee of around £500,000, with potential further payments dependent on his progress.

With Chelsea's youth team, he won the Under-18 Premier League title in 2017/18 and the FA Youth Cup the same season. He made his senior debut for Chelsea as a late substitute in their 2-2 draw with Sheffield United on 31st August 2019. By the time of his loan he had played 22 times for Chelsea's first team and was on the bench for their Champions League Final victory over Manchester City in May 2021.

He played for Scotland at Under-15, Under-16, Under-17, Under-19 and Under-21 before making his full international debut on 2nd June 2021 in a friendly against the Netherlands. His first start for Scotland came in the European Championships in a 0-0 draw with England at Wembley on 18th June 2021 where he was named Player of the Match. Unfortunately a positive Covid-19 test meant he missed Scotland's final group game which saw them exit the tournament.

Discussing his move to Carrow Road, Gilmour expressed his excitement at testing himself regularly in the top-flight: “I’m very excited to be here. I can’t wait for the season ahead. I’ve been looking forward to coming here, playing as much as possible and helping Norwich City compete in the Premier League. I spoke to the head coach. He called me and we had a nice talk about how he wants to play and how he sees me fitting in. Everything he said was what I want to do on the pitch, get the ball down and play nice football. He spoke really highly of his team and I wanted to come join here and help.There are very exciting times ahead, coming in for pre-season and seeing all the lads. Let’s get to it.”

Gilmour made his Norwich debut on the opening day of the 2021/22 season in the home defeat to Liverpool.

In October 2021 he was named in World Soccer's Top 500 most important players in the world.

He made 28 appearances in 2021/22 as Norwich finished bottom of the Premier League.

On 1st September 2022 Billy transferred to Brighton and Hove Albion for £7.5million with clauses that could see the fee rise to £10million. In June 2022 Gilmour extended his Chelsea contract to 2024 but left Stamford Bridge having made 21 appearances for the club. He had not played for Chelsea during 2022/23.

On 30th August 2024, after weeks of speculation, Gilmour signed for Italian side Napoli for an initial £12m, with add-ons worth a potential further £4m. Alos joining Napoli was fellow Scottish midfielder Scott McTominay. Gilmour had played 60 games for Brighton and re-unites with Antonio Conte who was manager of Chelsea when Gilmour was part of their youth teams.