News of Houllier’s death was first reported on Monday morning, with the Frenchman having recently undergone heart surgery.
Houllier was introduced as joint Liverpool manager alongside Roy Evans in 1998 but soon took sole charge.
In 2001 he led the club to an FA Cup, League Cup and UEFA Cup treble.
Tributes have poured in on social media for the former PSG manager including a response from star Lord Alan Sugar.
"Sad news on Gérard Houlier,” the Apprentice star tweeted.” Nice fellow. I can imagine that @piersmorgan will devote half @gmb show telling every one how he knew him so well and go back ages.”
The message prompted a strong response from Liverpool legends Jamie Carragher and Didi Hamman, alongside BBC presenter Dan Walker.
Walker, a host on the BBC’s Football Focus, said: “There is a time and a place Lord Sugar. May I humbly suggest that this is neither the time nor the place.”
Reds and Germany legend Didi Hamann said: “You obviously didn’t know him otherwise you’d pay him the respect he deserved. One of the few gentleman in the football world, which can’t be said of yourself.”
Liverpool hero and Sky Sports pundit Carragher added: “Delete this you [sear word] idiot.”
The 42-year-old previously posted: “Absolutely devastated by the news about Gerard Houllier, I was in touch with him only last month to arrange him coming to Liverpool. Loved that man to bits, he changed me as a person & as a player & got @LFC back winning trophies. RIP Boss.”