The Spanish full-back has committed his future to the Blues until 2024 and has ended speculation that he could join Barcelona this summer.
Azpilicueta joined the club back in 2012 and has won every possible major club trophy in the decade since. He is now aiming for success as Chelsea begin a new era under a consortium led by US chariman Todd Boehly.
The player told the club's website: "I am really happy to extend my stay at Chelsea, my home.
"It is almost 10 years since I first arrived and joined the club so I really feel the love and I am really excited for the new project we have in our hands.
"I would like to say thank you to Mr Todd and Mr Behdad for giving me the opportunity to keep my journey at this amazing club and I am really looking forward to continuing our adventure. I am a really proud captain and I hope we can share many good memories together."
Chelsea's new chiefs are also delighted that Azplicueta has committed the next two years to the club.
Co-owners Behdad Eghbali and Jose E. Feliciano said: “Cesar is a world-class leader on and off the pitch. He’s a Chelsea legend and exemplifies so many of the qualities and values as a player and a person we aspire to.
“We couldn’t be more excited for Cesar to be at Chelsea under our ownership as we continue to work to build a champion squad.”
Boehly added: "We are so happy that Cesar is staying at Chelsea for a minimum of two more years. We are thrilled with our captain showing his exemplary commitment and leadership yet again. There is still so much to do together.”