The English Premier League outfit had been rebuffed three times before they came back on deadline day with another offer which was again rejected.
For his part, the Hoops boss is hoping to complete the loan signing of Swedish keeper Viktor Noring from Trelleborgs and revealed he has had former Manchester United youngster Kenji Gorre, son of SFA youth coach Dean Gorre, on trial at Lennoxtown for a week.
Lennon said: "I am delighted that we have kept all our main players.
"We have added Tom Rogic, Rami Gershon and hopefully Viktor - we are just waiting on the paperwork coming through - so it has been a decent window for us.
"There was another bid in yesterday (for Hooper), again, an improved offer.
"I am not going to go into the figures but it was substantial.
"We made our position clear and we stuck to that.
"I knew what has happening so it wasn't nervy for me.
"It might have been for supporters but there was a lot of rubbish and speculation being bandied about, a lot of nonsense, but I suppose that comes with the fun of it all."
Keeper Fraser Forster will return for the William Hill Scottish Cup tie against Raith Rovers at Stark's Park on Sunday after recovering from a neck injury and winger James Forrest is back from a hamstring injury.
Lennon is hoping that Georgios Samaras and Emilio Izaguirre, who picked up hamstring and knee injuries respectively against Kilmarnock in midweek, will be back for the Champions League last-16 clash with Juventus at Parkhead on February 12.
He said: "They had scans yesterday so we are hoping that they will both be fit for Juventus.
"It is a small tear for Georgios but we are going to be aggressive with his rehabilitation and our medical people, I wouldn't say they were confident, but they think he has a chance of making Juventus and we are hoping Emilio should be okay."
On Gorre, the Hoops boss said: "He has been released by Manchester United so we have had him in for a week to have a look at him.
"He has done okay, he is a winger, 18, and he is a development-type player."
Meanwhile, Celtic new boy Tom Rogic has told how a footballing X-Factor competition helped him launch his professional career.
The 20-year-old Australian checked in at Lennoxtown this week after securing a work permit, following his move from Central Coast Mariners.
Hoops boss Neil Lennon snapped up the attacking midfielder on a four-and-a-half-year contract for a reported fee of £400,000, after he had trained with the Celtic players in Marbella during their winter training camp last month.
When meeting the media at the club's training complex today, Rogic revealed his break came when he was invited to the Nike Football Academy at Loughborough University after winning The Chance, a football talent search competition organised by Nike and run all over the world.
Asked if there was an X-Factor element to his breakthrough, Rogic, who has since won four caps for the Socceroos, laughed then replied: "In a way I guess you could put it like that.
"About two years ago, I was just playing local football. The Chance programme was to find unidentified talent who had not been at professional clubs.
"Playing local league at the time, I gave it a try and ended up being part of the Nike Academy, based in Loughborough, England, for about six months.
"Not being able to sign for any clubs because of work permit reasons, I headed home and signed for Central Coast, where I had a productive 12 months and I guess it has all culminated in signing for Celtic.
"The past 12, 18 months seem pretty crazy but I have put in a lot of hard work and believe I have earned the opportunity.
"It is obviously a massive club with a great history.
"When they were interested I was very flattered and, from when I met the side in Marbella and coming back and seeing Celtic Park and Lennoxtown, it altogether seemed like a great move. It happened very quickly it is a great move and I am looking forward to the challenge."
Lennon recognised Rogic's relatively late entry into the professional game but had enough confidence in the player to put him alongside some exalted company.
The Hoops boss, who tried to sign Wolves' Kevin Doyle before the transfer window closed, said: "I think he has had a meteoric rise, but long may that continue.
"We are not saying he is the Great White Hope or anything like that but I think he will be invaluable as the season goes on and, over the next two or three years, we hope he blossoms into the player we hope he can be.
"There are times you get late developers who go on to have fantastic careers.
"Roy Keane was playing at Cobh Ramblers and a couple of months later Brian Clough gave him his debut (for Nottingham Forest) at Anfield against Liverpool and Roy didn't look back.
"Tom has matured, physically, although I think he has a little bit more to come in that aspect, but athletically and football-wise, for his age, he is very good."
Rogic will not be in the squad for Sunday's William Hill Scottish Cup tie at Raith Rovers, but Lennon insists he could be involved in the Champions League last-16 clash with Juventus on February 12.
The former Celtic captain said: "We are just hoping he adjusts quickly to the environment and if he does then he will have every chance to be in the squad."
On his attempt to get Doyle, the Northern Irishman said: "I wanted him to come in and play with Gary (Hooper) but Wolves were firm on that as we were regarding Gary (not going to Norwich).
"Kevin knows what the club is about but he is pretty committed with Wolves for the foreseeable future and we respect that."