The Canaries are believed to have made four bids for Hooper and had all rejected by the Hoops.
But with talk of the Carrow Road club making a fifth bid to prise Hooper away from Parkhead as the clock ticked towards the 11pm deadline on Thursday night, Celtic boss Neil Lennon took to Twitter.
"Contrary to reports there have been no fresh bids for Gary and even if there are they will be rejected..he is NOT for sale," he tweeted.
Celtic were frustrated in their own attempts to bolster their strikeforce, with a bid to take striker Kevin Doyle on loan knocked back by Wolves.
Norwich brought in one striker on deadline day, signing Luciano Becchio from Leeds in a swap deal involving Steve Morison.