The Spain international sealed a move back to his beloved Barcelona last month, but he says Wenger is the one that convinced Arsenal to allow him to go back.
He also admits that he needed his years under Wenger to become the player he is today.
The Spanish press often accused Wenger of almost abducting Fabregas from the Barcelona academy - but he insists that is totally the wrong idea.
"That is the wrong picture of him, had it not been for him, I would not now be a Barca player," he told El Pais.
"Without him I would not have made my debut by 16, played in the final of the Champions League at 18 and been team captain by 20.
"Without him I would not be a Barca player now, he convinced the owners of Arsenal, who would not sell under any circumstances, to lower the price."
Whilst admitting that he is forever grateful to Arsenal, he insists that he never gave less than 100 per cent.
"I have everything, I could not have done more, my performances were fine and I played as much as I could," he said.
"In terms of titles, I am bitter about that - missing out on winning the Premier League about three times, I would have liked to have taken that, but it could not happen.
"But London will always be my city, I did not make great friends, but friends from the changing room and Wenger, you can look no further I would be nothing without him, no world champion, nothing.
"I talked with him a lot, his words to me will last a liftetime. I could hardly talk when I left, but I did speak with him. But what he has given me is priceless."
He admits that he had offers to leave Arsenal from the age of 18 - but he refused to confirm who they were, with reports suggesting Real Madrid were always following him.
"Since 18 I was made offers, I am not going to name names but that is the truth of it," he said.
Now back at Barcelona, he insists that he still is not the finished article as a footballer.
"I feel I still have much to learn, this team is highly mechanised and there are things I have to catch up on particularly in defence," he said.
"I have never seen a team that is so focused on the attack-defend transition - playing against Barcelona is very complicated but playing at the club is not so easy and that is the challenge.
"I honestly feel that at times I may hinder them, but they are good at fixing it and hiding it, I must adapt to them and learn."
The former Arsenal skipper admits that training at Barcelona is something he has never witnessed before.
He said: "It is the most beautiful thing I have seen in my life, all you hear is the ball going - tap, tap, tap - I have never seen so much training at this level."
And he admits that he will have to bide his time to play - insisting that only Xavi, Andres Iniesta and Lionel Messi are guaranteed to start.
"It is clear that only players like Xavi, Iniesta and Messi could complain about a lack of playing time, and if they did complain I would respect that, so I will play when I play," Fabregas concluded.