The Nigerian international, who joined Chelsea as a 19-year-old in 2006, has made 261 appearances and tasted plenty of success - one Champions League title, four FA Cup medals, one Premier League triumph and a League Cup victory.
"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," Mikel said in a statement on Chelsea's website.
"Last season to win the Champions League was even more special," he added, "and I hope these next five years will bring even more success and I can win trophies with the new players we have here."
Originally an attack-minded midfielder, Mikel adapted to a more defensive role under former Chelsea manager Jose Mourinho and is the team's anchorman in front of the back four.
"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," he said.
Mikel was embroiled in controversy recently after Chelsea accused referee Mark Clattenburg of "inappropriate language" towards the player during the league clash with Manchester United in October.
However, investigations by the Metropolitan Police and English FA found there was no case for Clattenburg to answer.
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