Former Football Association executive Bevington joined the club to review and evaluate the managerial position and playing staff at Villa Park in March.
He follows David Bernstein and Lord Mervyn King after the pair quit the relegated side last month and stating their new football board had found it impossible to implement a new structure.
Bevington told the club's official site: "I explained to (chairman) Steve Hollis a few weeks ago that I would not be looking to take on a full-time role with the club, but agreed to remain as an advisor until the end of the season.
"I know how hard Steve is working on a number of levels and I hope he can conclude the ownership and managerial positions very soon.
"I have enjoyed working with Steve and Brian Little - a man who clearly cares so much for the club and will do everything he can to help it succeed.
"I'd also like to make particular reference to Eric Black
Eric has been a true professional to work with after taking on the manager's role in the most difficult circumstances.
"There is a huge amount of work ahead for Aston Villa FC
A club of its size with its great support should be competing at the higher levels of the Premier League, not in the position it currently finds itself.
"To move forward, now more than ever, it is crucial the club makes the right calls on the big decisions it is faced with."
Chairman Hollis, who himself only joined Villa in January, thanked Bevington for his help
"I'd like to place on record my thanks to Adrian for his contribution and professionalism," he said.
"Over a short period of time, he has provided a great deal of football knowledge and experience - both to the club and to me personally.
"Adrian gave me his word he would remain with the club until the end of the season
Now that time has come we wish him well for the future with his various football commitments."
Villa were relegated from the top flight for the first time since 1987 in April and finished bottom of the Barclays Premier League with a club-record low total of just 17 points
Former Leicester chief Nigel Pearson and ex-Chelsea boss Roberto Di Matteo are the frontrunners for the manager's job with caretaker Eric Black not expected to stay at the club
Owner Randy Lerner is also closing in on a sale, which could be concluded within weeks.
Source : PA
Source: PA