The 21-year-old has established himself in Antonio Conte ‘s first-team squad this season and scored on his full debut fornthe club, in a 5-1 win over Nottingham Forest in the Carabao Cup.
Upon signing the new deal, which will now run until 2022, Musonda said: ‘I am very happy and very proud. I came here very young and am very happy to continue my journey here. I love this club so it’s a great moment for me and my family.
Now I want to establish myself and progress into the team and stay here permanently.’
Club director Marina Granovskaia said: ‘We are very happy Charly has committed his future to the club. He is an exciting talent who we believe can develop into an important first-team player and we hope he will be a part of Chelsea’s successes for a long time to come.’
A Belgian international at five age groups from Under-15 to Under-21, Musonda won the FA Youth Cup twice with the Blues Academy, as well as the Under-21 Premier League and UEFA Youth League.
A skilful attacking midfielder who can play as a No10 or an out-and-out winger, he had loan spells with Real Betis in the Spanish top flight during the 2015/16 and 2016/17 seasons.
Musonda made his Premier League debut as a substitute on the opening day of this season and has five first-team appearances to his name.