The 33-year-old came third during last night's final, and admitted Katie was a much-needed breath of fresh air to the atmosphere.
He told Emma Willis: "You're stuck in this environment and it is so intense. Katie came in fresh and it was someone else you could talk to.
"I was happy to see her in. I think Katie's awesome. Good luck to her."
The model has also admitted that being on the show has given him a much needed confidence boost.
Speaking to OK! magazine, he said: "This was an opportunity for me to show who I really am.
"I can deal with negativity more now. Before I was quite insecure. The reaction I've had I couldn't feel better about. I'm so grateful for this opportunity.
"I hate playing the sympathy card but when I lost my dad in 2005, I was a lost soul.
"When my dad was around I always had hope that he would get better and when I lost him, I lost the plot."
Calum also revealed his plans to make a movie about George, adding: "I was writing a film for the last three years about my dad. It's a film documentary so I will be presenting it. It's called My Best."