Lennon was referring to the situation surrounding newco Rangers and the rejection of their application to the Clydesdale Bank Premier League, with the Hoops' Old Firm rivals still unsure of which level of the Scottish Football League ladder they will enter this campaign.
Reigning champions Celtic were one of many SPL clubs to vote against Rangers' admission into the top flight but Lennon is keen to put the issue behind him and wants the fans to do the same. He told the club's official website: "We cannot let outside negative influences dictate the mood at Celtic."
He added: "We are very optimistic and we are very much looking forward to the season but we need our fans right with us.
"We are now looking forward and not back, we have a vibrant young team, I want to progress this team as far as I can but we cannot do this without the fans' support.
"We must now move on, and move on with a collective unity between the supporters and the club and the team. We enjoyed that unity last season and we now need this to continue more than ever."
Reports have suggested that Celtic's financial stability is reliant on their Glasgow neighbours, something the club itself has rebuffed, but Lennon admitted everyone needs to do their bit and implored supporters to keep following the team.
He said: "We now know what the situation is and where we are and it is a situation we must now deal with.
"We need to stand strong, shoulder to shoulder and all work together to continue to move the club in the right direction.
"We will need the supporters to be right behind the team. We want as many fans as possible to come back to the club and take their seat at Celtic Park and invest in the club as much as possible."
Source: PA
Source: PA