The Rangers manager turned 40 this week.
Houllier said: "Every person who has worked with Stevie will tell you he had intelligence, desire and extremely strong character.
"He has never stopped putting in hard work to succeed and he sacrificed a lot to be where he is today.
"There are qualities that are very important to know about him.
"Stevie is loyal to his family, friends, team-mates, clubs, to his agent, staff and the players he manages now.
"He is also really generous, he has a big heart and there are many things that he did to help people that you will never know about.
"Stevie is also incredibly humble. He has ambition, yes, but is is combined with humility
"I watched him grow from a kid to become one of the best players in the world and an example of what a captain should be.
"But his personality has never changed. He is still the same Stevie and I'm sure that he will be a top manager because he will work towards that.
"He is not arrogant, he started with the youth at Liverpool's academy and is now building his way through this new career."