The England U21 international, who spent time working with Frank Lampard at Derby last season, has committed to terms with the Blues through to 2024
Mason Mount has committed to a new five-year contract at Chelsea, with that deal set to take the highly-rated midfielder through to 2024.
Goal revealed two weeks ago that fresh terms for the England Under-21 international were close.
He is a highly-regarded product of a famed academy system in west London.
Mount also spent time working with Frank Lampard during a loan spell at Derby County last season, so the new Blues boss knows all about his current ability and future potential.
Chelsea have moved to ensure that the 20-year-old will remain on their books as they seek to be the ones to benefit from any further development.
There had been less than two years left to run on his previous contract, but an improved agreement has brought any uncertainty surrounding him to a close.
Mount is delighted to have penned a new deal, telling the club’s official website : “It’s a massively proud moment for myself and my family.
“I joined this club at six years old and it was always my goal to play for the first team one day.
“I’m really looking forward to the coming season now and working hard to have an impact here at Chelsea.
“I’ve been at the club for a long time already and hopefully I’ll stay for a long time to come.”
Blues director Marina Granovskaia added: “Mason has come right the way through the Chelsea academy and has always stood out as a fantastic talent and dedicated individual.
“We have monitored his development extremely closely while he has been out on loan and believe he is now ready to be a member of our squad competing at the top of the Premier League.
“Like another of our Academy graduates, Ruben Loftus-Cheek, we are delighted Mason has committed himself to the club this summer and look forward to an exciting future ahead.”
Loftus-Cheek has already committed to a new five-year contract of his own with Chelsea.
His deal is worth £120,000-a-week, with Mount now hoping to tread a similar path into the Blues’ first team and senior England set-up.
Another of those he will be using as an example of how to make the grade at a Premier League heavyweight is Callum Hudson-Odoi, with those at Stamford Bridge hoping that the teenage forward will be the next to buy into Lampard’s vision for the club.