Hooper blasted 82 goals in 127 games during his three-year stint at Celtic before signing for Norwich last summer for £5m.
And he established himself as a firm hero with the Parkhead fans.
Now Lennon expects Griffiths, who signed a three-and-a-half-year deal last night from Wolves, to show he has the quality to bridge the gap between prolific domestic striker and Champions League marksman that has been left by Hooper's departure.
Lennon said: "We are delighted we have Leigh in. We have been looking for a consistent goalscorer since Gary left and I believe and really hope that Leigh will fit the bill.
"I like players who have that bit of gallus about them on the park and Leigh certainly has that.
"He is a hungry boy and he's Scottish and it will be good to have another home boy in the dressing room. I believe firmly that Leigh will fit in very well at Celtic Park. He is a player we like very much.
"We saw how well he did at Hibs last year and we have had him watched again with Wolves and he has come on again."
The Hoops gaffer has no doubt Griffiths, who scored 39 goals in two seasons on loan at Easter Road in the SPL, can take that form into the Champions League.
Lennon said: "I believe Leigh has improved a lot, he is getting stronger, and he is a great finisher who nearly always hits the target with either foot.
"He is also very mobile and has a great work ethic. Perhaps we will need to work on his upper body strength, we'll see.
"But for me there is a strong chance that Leigh will get better again and show he can produce the type of form he has done in Scotland in a Champions League context."
Lennon has been disappointed with some of the adverse reaction via social media to Griffiths' signing and revealed he has spoken to the striker regarding his responsibilities as a Celtic player.
The manager said: "Leigh knows the intensity that is involved with being at Celtic and I guess it is up to me to help him change perceptions of him. But he can also do that by the way he contributes on the park."
Griffiths is expected to join Celtic's other new signing Stefan Johansen in the squad for tomorrow's visit of St Mirren.
Lennon, meanwhile, confirmed striker Mo Bangura has been freed, but also revealed he had failed in a €3m bid for a Turkish-based striker who he may revisit in the summer.
The Hoops boss said: "We did put a big bid in that matched his get-out clause but there were issues on their side. He is a player we rate highly.
Meanwhile, Shrewsbury Town have signed young Celtic striker Bahrudin Atajic on loan until the end of the season, Mikey Miller has been loaned out to Dumbarton and Joe Chalmers has been sent to Falkirk.