The Frenchman has not been in management since leaving Lyon in 2007, winning two league titles with the French club following his Liverpool departure in 2004.
Welcome back: Gerard Houllier returns to the Premier League by taking charge of Aston Villa
Having finished sixth in their last three seasons, Houllier faces a stern test in replacing his predecessor Martin O'Neill. With this in mind Sportsmail looks at five big tasks he immediately faces at the club.
Sort through the dead woodMany players came and went during O'Neill's time at the club, but a few still remain having been denied first-team chances.
Multi-million pound signing Curtis Davies has been troubled with injury but, along with other crocks Fabian Delph and Steve Sidwell, he has failed to make a major impact in recent times.
Old favourite: Heskey was brought to Liverpool by Houllier and may find first team chances easier to come by
Many players who were on the scrapheap will see Houllier's arrival as a second chance and the Frenchman has several months to find some use from O'Neill's cast-offs.
Ensure future of Liverpool rejectsBrad Friedel was brought to Liverpool by Houllier's predecessor Roy Evans. But following Evans's resignation, the American stopper was sparingly used by Houllier before being given a free transfer to Blackburn.
Stephen Warnock will also be wary of Houllier, with the left-back loaned out twice and failing to make an appearance for Liverpool under the Frenchman's reign.
Dispensable: Bard Friedel and Stephen Warnock hardly featured during Houllier's time at Anfield
With both players a key part of Villa's starting XI, Houllier will need to ensure the pair he has confidence in them, as replacements will not be hard to come by, especially with a closed transfer window.
Proof in youthThe emergence of Steven Gerrard aside, Houllier's record for bringing through youth talent at Liverpool was relatively poor.
With the purse strings seemingly closed at Villa Park, he may have to turn towards younger talents at the club to take the club forward.
Potential: Marc Albrighton broke in to the first team under caretaker boss Kevin MacDonald
The emergence of Marc Albrighton should provide encouragement, while striker Nathan Delfouneso is a bright prospect that Houllier can get the best out of.
Win over players and supportersSenior players such as skipper Stiliyan Petrov, Luke Young and James Collins have all backed caretaker boss Kevin MacDonald to take the full-time job, leaving Houllier at a disadvantage from the start.
Not in favour: Skipper Stiliyan Petrov backed Kevin MacDonald to grab the Villa vacancy
Supporters will also be cautious over his mixed time at Liverpool. Despite a treble winning season and a season as runners-up in the Premier League, life at Anfield ended badly after two below average final seasons.
Players and fans alike will be cautious over his rustiness and he may find the league has moved on since his last appearance.
Better transfer dealingsWith money not available in the quantities it was at Anfield, Houllier will have to improve his hit rates with each of his purchases should he make any.
Big success: Signing unknown Sami Hyypia proved to be one of Houllier's managerial masterstrokes
In his time at Liverpool, for every Sami Hyypia and Dietmar Hamann there was a Bruno Cheyrou or Igor Biscan who would fail to live up to expectations.
If he does choose to buy his way out of trouble, he can not afford to be as wasteful. There is not much room for tolerance in the Villa transfer kitty.
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