Kenyon left league rivals Manchester United in 2003, joining Chelsea in 2004 following a period of gardening leave and under owner Roman Abramovich took charge of the business side of the club with the long-term aim of becoming one of the most profitable and best supported clubs in the world.
He will remain at Chelsea as a non-executive director and continue to represent the club in various capacities, including committee roles with UEFA, European football’s governing body.
"I am certain I have at least one major challenge left in me," Kenyon told the official club website. "I am extremely proud of my time at Chelsea and of the friendships I have forged with everyone here. I have been in football for 15 years and I can say with great certainty and pleasure the experience at Chelsea is one of the best I have had."
In 2008 Kenyon said the club retained their "ambitious" target of operating profit break even by 2010 but in February this year Chelsea revealed that they made a £67.5 million loss for the financial year to the end of June 2008.
