Club statement: Paul Faulkner
Prior to his joining Villa, Paul had worked closely with Villa Chairman Randy Lerner in a variety of capacities within his organisation.
Having discussed his re-engaging with the Chairman's broader business while remaining involved with Villa in a non-operational role, agreement could not be reached.
On the strength of many productive years together, and a longstanding friendship, Paul has parted on good terms.
He has offered his support to the Villa organisation to ensure a smooth transition.
Robin Russell, who was recruited by the Chairman in 2006 to come in as Chief Financial Officer, and with whom he has now worked for more than 20 years, will step in as acting Chief Executive to maintain continuity.
Paul Faulkner said: "I would like to thank Randy Lerner for the opportunity to become involved with Aston Villa and for the relationship we built over years, which pre-dated my time at the Club.
"To the Villa fans, I am grateful for their support over the years, and for their passionate love for and loyalty to this great club, which deserves the very best.
"I would like to make particular reference to the wonderful Villa staff both at Bodymoor Heath and Villa Park. They are an incredible group of people and it's been a privilege to lead and work with them on a daily basis. Villa is best in class in so many ways off the field and I only hope that success on the pitch follows.
"I feel very humbled to have been able to spend such a long period of time amongst such special people at such a special club and I wish them, Paul Lambert and the squad all the very best for the future as I look to embark on the next stage of my career and a new challenge."
The Villa Chairman also added: "Paul has been fantastic in his role at Villa and more broadly as a colleague over the years. I offer him my deepest thanks."