The 24-year-old is yet to sign a new contract at the Scottish Premier League champions after scoring 17 goals in all competitions this season.
Hooper, who joined Celtic from Scunthorpe in 2010, has been linked with a move to England in recent months, while Manchester United were touted to be interested in Victor Wanyama.
But Lennon is confident there will be no big-name players leaving Parkhead next month.
“I’ve spoken to a number of the players over the last week or so just to say: ‘Look, there is going to be a lot of speculation. As far as I’m concerned, you won’t be leaving the club and just concentrate on what you’re doing’.
“We are in four competitions. We are in the last 16 of the Champions League. We are top of the league, the semi-final of the League Cup and the last 16 of the (Scottish) FA Cup.
“Why would you want to give that up now having worked so hard to get there in the first place?
“I don’t think there are many other clubs that can offer that and if they can, then they will be cup-tied anyway.
“What’s the rush? Why go now when they can maybe go further down the line?
“Or maybe we are all pre-empting things. Maybe the players don’t want to go anywhere. The majority of them seem to be very, very happy here.”
Get enhanced odds of 18/1 on Andy Murray to win Wimbledon or 10/1 on Novak Djokovic when you open a Paddy Power account.