Chelsea signed Gilmour from Rangers in 2017, as a highly promising prospect.
The Scotland international was handed his Blues debut by former manager Frank Lampard, and at one time became a big part of the team before injury struck.
The 21-year-old has now sealed a transfer to Brighton, and he has admitted it was time to leave Chelsea due to a lack of games.
Asked whether he felt he needed a fresh start after the deciding to leave Stamford Bridge, Gilmour said: “Yeah, I think so.
“Of course it was a tough decision but I wanted to play football, that’s the main aim for me, to come in and enjoy my football and get regular game-time. It was a bit of a no-brainer.
“For me, Brighton play great football with a style I like to play. The manager is highly thought of as well so I was keen to come here.”
Brighton boss Graham Potter was pleased with the signing and said he ‘cannot wait’ to start working with Gilmour and is ‘really excited’ by his potential.
“Billy arrives with a fantastic pedigree, having played in the Premier League and Champions League as well as for Scotland at last year’s Euros,” Potter said.
“He will complement our existing midfield options. That experience at quite a young age shows the strength of character he has and we’re really excited by his potential.
“Now it’s about allowing him the time to get used to a new environment and settling in to our club. We can’t wait to work with him.”
There’s no need to sell Gilmour , he should go out for loan. A guy who is youug and talented player who can fill a whole in the team in future now sold to Brighton. Chelsea as a team sometimes make a mistakes of selling of young talented players. Looking at Tomori, Tammy, Guehi, etc all these players are doing well in their teams, decisions must be right.
If it is true that players TT needs are not in now, then I will advise that they should plan early as possible to get them in January transfer window