The Duke of Cambridge, now 37, was turning 13 in 1995 when he attended afternoon tea as part of his birthday celebrations.
But Naomi, speaking on ITV’s Lorraine, revealed she surprised Prince William with a group of supermodel friends.
She said: “I do remember that. He was so sweet, he was blushing, he came home from school to find these women in his home.
“He was adorable. Princess Diana was so gracious.
“He came home from school to find these women in his home”
“I remember she opened the front door.
“All our drivers thought they were going to collapse. So hands on.”
She added: “I loved their [Harry and William’s] mother, she was amazing, and she loved Africa.
“And grandad, President Mandela, loved Princess Diana very much.”
The model also spoke about Prince Harry and Meghan Markle’s plans to visit Africa with their new son Archie this autumn.
She said: “Ecstatic. I think Prince Harry and the Duchess Meghan Markle are doing, they’re re-writing history.
“They have no idea what they’re going to do for the African continent.
“They’re going to love it, they’re going to find such peace there, little Archie’s going to love it.”
Naomi is 49 and turning 50 in May next year but she isn’t worried about the prospect.
She said: “I’m so embracing of it.
“I can’t wait, I feel good.
“It’s a bit odd I must say though when I’m doing a fashion show and I’m between my two friends’ daughters.”