Mikel’s football career began at the age of 12 when he was picked from over 3000 young to play in a Pepsi Football Academy. He then played for Plateau United where he was selected to play for his country at the FIFA 2003 Under-17 World Championships held in Finland.
In the summer of 2005, Mikel played for Nigeria at the FIFA World Youth Championships held in the Netherlands where Nigeria reached the final, losing out 2–1 to Argentina. Obi won the Silver Ball after being voted the tournament's second best player.
In summer 2006 Mikel signed with Chelsea for £16M and made his first start for them in the UEFA Champions League against Levski Sofia and later scored his first goal in their 6-1 FA Cup victory over Macclesfield Town. He quickly enjoyed success with Chelsea’s when they won the League Cup Final in 2007.
Under the watchful eye of his manager Jose Mourinho, Mikel’s playing role was mainly as a defensive midfield position where he excelled in the 2009/10 season winning both the Premier League and FA Cup as part of Chelsea's double-winning team.
Todate, Mikel’s career has seen him play 211 League and Cup games, scoring 2 goals. He won with Chelsea the Premier League title in 2009/10, the FA Cup in seasons 2006/7, 2008/9 and 2009/10, the League Cup in 2007 and the FA Community Shield in 2009.
Mikel’s senior international career started in August 2005 and shortly thereafter he was picked for the Nigeria squad for the 2006 African Cup of Nations. Thereafter, during the 2008 African Nations Cup in Ghana, he scored to help Nigeria qualify for the quarterfinals against hosts, Ghana where they narrowly lost 2–1. His current international career comprises of 37 caps and 2 goals.