Houllier admitted "we would sign him tomorrow" if Benzema becomes available.
The 25-year-old made a multi-million pound move from Houllier's previous club, Lyon, to Real last year but is reported to be unsettled.
It would be a massive coup for Villa if Houllier could attract such a quality player.
The Villa boss said: "If Karim wants to come and play at Aston Villa, we would sign him tomorrow."
Houllier is already poised to sign former Arsenal midfielder Robert Pires in the next two to three days.
Pires is a free agent following his release by Villarreal last summer.
Gunners boss Arsene Wenger and French coach Laurent Blanc have both given their backing to the potential move.
Houllier has made it clear he needs to sign new players during the January transfer window.
But he has ruled out making a move for Manchester United striker Michael Owen, who played under him at Liverpool.