Some sections of supporters called for Houllier to be sacked after Villa's last home game with Wolves a fortnight ago.
But Houllier recognises their importance to the midlands club, who entertain Newcastle on Sunday after an encouraging 2-2 draw at Everton.
The Villa manager said: "All I can say is that we need the fans. We are in this together not only the team but the staff, the management, the owner and the chief executive.
"The fans are our 12th man and what we want is for them to be behind the team and we need that more than anything else at the moment.
"They are close to the team and they want us to do well. We can give them back the effort and the will to win."
Source: PA
Source: PA