The 46-year-old journalist - who now fronts CNN's Piers Morgan Tonight - says he hates Kate, 38, and the supermodel despises him in equal measure.
He said: "She doesn't like me, I don't like her.
"Kate Moss is utterly horrific. If people actually knew what she was like they would never, ever be interested in her again.
"She's just a real, spoilt little madam from Croydon. There's nothing wrong with Croydon - I was brought up near Croydon. But she's just a vile little creature."
Moving on to the topic of Madonna, Piers - who has banned the Hung Up singer from his chat show - took aim at her toned physique.