Houllier has shaken hands on a three-year deal with Villa but has to agree a departure date from his role of technical director with the French Football Federation.
If all goes to plan, the 63-year-old Frenchman is set to be at the helm for the first time for the home Carling Cup game with Blackburn on September 22.
Houllier will not attend Monday's Premier League clash at Stoke while he thrashes out the terms of his exit from the FFF.
He will return to England for the home match with Bolton on September 18 but Kevin MacDonald will remain as caretaker boss for the next few days.
Houllier said: "I take great pride in my appointment as manager of Aston Villa. It is a great honour for me.
"Why am I here? One of the reasons is that I think Randy Lerner [owner] and Paul Faulkner [chief executive] have great enthusiasm, dynamism and honesty and they convinced me of their ambitions for the club.
"I had a good job with the FFF but I had a desire to return to English football - although it is not a case of unfinished business because I did well at Liverpool and won six trophies."
Houllier confirmed that MacDonald will not be part of Villa's first-team set-up.
He said: "I spoke to Kevin this morning and he prefers to go back to his role as reserve-team manager.
"He has done a very good job and I trust him and I am sure our relationship will be good."