Hollis was a partner for over 20 years and worked throughout the world as a board member on KPMG's boards in the UK, Europe, Middle East and Africa.
Prior to his retirement from the company in 2013, Hollis returned to the Midlands and chaired KPMG's Midland Practice.
He is well-known in the Midlands, having held the post of deputy chair of the Greater Business & Solihull Local Enterprise Partnership and, more recently, chairman of Birmingham Metropolitan College.
In a statement on the club's website, Hollis said: "When Randy (Lerner) approached me last November, chairing one of the UK's best known football clubs was not, quite frankly, on my list of possible opportunities.
“As I have got to know Randy and spent more time with Tom Fox and Rémi Garde it has become increasingly clear that a strong board that drives the necessary discipline and leadership will be at the core of the changes that are needed to overcome the under-performance Aston Villa has experienced over the last five years.
“As we have witnessed in the Premier League this year with other clubs - money no longer buys success. Randy has consistently provided financial backing no less so than last year.
“Our future success however lies in building a winning culture that is underpinned by a commitment to continuous improvement both on and off the pitch.
“The business of football is no different to any other business in this respect. We have the talent and great assets at Villa Park and Bodymoor Heath.”
Lerner added: “Steve has taken the last six weeks to become familiar with the deeply serious predicament in which the club has found itself and has my total support to address the issues we face.
"We pursued Steve's candidacy in order to continue and strengthen the efforts that commenced in the summer of 2014 with the hiring of Tom Fox.
“Tom and Steve have spent time throughout December and early January and will therefore be in a position to work closely and immediately across all areas of the club.
“We anticipate that Steve will give us additional reach within local business circles as well among government and quasi-government organisations.
“Steve has consistently demonstrated his commitment to Birmingham not only in his private commercial roles but also recently as deputy chair of the LEP and chair of the Birmingham Met.”