The 20-year-old Albania international has made three appearances so far off the bench this season after returning from a loan spell at Southampton.
Broja scored nine goals in 38 appearances across all competitions for the Saints during his loan spell last season and attracted interest from the likes of Everton, Newcastle United and West Ham United in the summer transfer window but Chelsea refused to sell.
Broja has been at Chelsea since the age of nine and has come through the youth ranks to reach this far.
He made his senior debut for Chelsea in a 4-0 Premier League win over Everton in the 2019/2020 season and signed a new five-year contract last summer.
But Chelsea have moved further to secure his long-term future by adding two more years to his existing deal.
Speaking to the club website, Broja said: ‘I’m lost for words really just thinking about it. It’s the club I’ve dreamed of playing for my whole life, the club that I support and the club that I love. I’ve been here since I was a boy so it’s a surreal feeling for me and my family.
New owner Todd Boehly was very pleased to extend Broja's contract saying: ‘We are delighted Armando has committed to Chelsea. He is a young and exciting striker and a big part of our plans moving forward.’
Broja has scored four goals in 14 appearances for Albania.
