The 25-year old Nigeria international has penned a deal which will see him remain at Stamford Bridge until 2017.
"Chelsea seems like my home now because I have been here for over six years and I enjoy my time here," he told the club's official website.
"I come into the training ground every day to work and I value my time there. I am happy and want to keep going and win trophies for this club.
"I have basically won everything with Chelsea and those years have been really special for me, winning trophies with big names like Didier Drogba, John Terry and Frank Lampard who have had very long Chelsea careers.
"Last season to win the Champions League was even more special and I hope these next five years will bring even more success and I can win trophies with the new players we have here.
"Being 25 I think I am now hitting my peak but as a player you want to improve every day and there is still room for that. I want to learn from the players and the manager and I just want to keep going."
Mikel joined the Blues from Norwegian club Lyn in 2006 and has since made 261 appearances, winning the Premier League once, the FA Cup four times, the League Cup, and the Champions League.