The midfielder, who had most recently played for Kuwait SC, called time on his 20-year career on Wednesday (AEST).
Mikel spent the majority of his playing days with Chelsea, winning two Premier League titles, the Champions League and the Europa League.
The enforcer also lifted the FA Cup three times during his time with the Blues and got his hands on the Carabao Cup in 2007.
Mikel won 91 caps for the Super Eagles and the highlight of his international career was a 2013 Africa Cup of Nations triumph.
He posted on Instagram: "There is a saying that 'all good things must come to an end', and for my professional football career, that day is today.
"I look back at the past 20 years of my career, and I must say that I am very satisfied with all that I was able to achieve and more importantly the human it has helped shape.
"All of this would not have been possible without the unwavering support of my family, managers, clubs, coaches, team-mates and most importantly my ever-loyal fans. You supported me through my highs and lows, even on days that I did not live up to your expectations. I say a big thank you.
"I will also like to encourage everyone who I may have inspired one way or the other in the course of my career to never give up on their dreams, for every time you think about quitting, remind yourself why you started.
"This is not goodbye, it's the start of another journey, another chapter of my life. I look forward to what the future holds and I hope you will walk with me. Thank you."