The 23-year-old has joined the Scottish Champions from Wolverhampton Wanderers, and Lennon feels that his goalscoring abilities will be a huge boost to the Hoops.
"I've known Leigh Griffiths for a while and he scored 29 goals for a struggling Hibs last season," Lennon told BBC Radio 5 live.
"He then started this season well for Wolves. We've been looking for a scorer in the box and we think he'll just keep getting better, developing into an all-round striker. And strikers, of course, are at a premium."
Griffiths has won four caps with the Scottish national side.