Holmes made 20 defences of boxing’s biggest prize – second only behind Joe Louis – and says Joshua has the potential to achieve even more.
Holmes was at ringside to watch the Olympic gold medallist make it three wins out of three in the professional ring last November.
Joshua has been kept out of the ring since then with bicep and shoulder injuries – but is back to face Dorian Darch in front of the Sky Sports cameras in Cardiff on Saturday, February 1.
Holmes reckons the 24 year-old could become a ring legend.
He said: “There are things that he does wrong, but his quickness makes up for that and with the right training, I think you have got a champion here.
“Maybe he could even beat my record. I told him that.
“If I was his age again, I would be champion for a long time.
“And who is out there ? There’s only the Klitschko brothers and they don’t want to fight anybody who can really compete.”
Holmes is remembered for having one of the best jabs in boxing – and says that the punch that can help Joshua become a legend.
“The Klitschkos are good fighters who base everything on the jab,” he said.
“That’s what this kid has got to learn.
“You have a big boy here who is capable of boxing properly, not like Lennox Lewis. He was great, but had no jab.”