The singers performed together in Atomic Kitten, along with Natasha Hamilton, prior to Katona's marriage to Westlife's Brian McFadden. However, the two lost touch after Katona left the band to have her first child.
McClarnon told Now: "I don't speak to her but if I see her around I will.
"I might even pop down to Dancing On Ice and say hello."
The 29-year-old added: "I really do think she's turned a corner. You've just got to look at her body. I'm really proud of her."