The 38-year-old was among the celebrities ho attended the Kiss FM Halloween Haunted House Party at the SSE Arena in London.
Other guests – such as the X Factor finalists – dressed for the occasion in spooky costumes, but Katie decided against fancy dress, instead wearing an all-black ensemble.
Katie matched leather-look leggings with a black jumper and trainers, and kept her long blonde hair loose and poker straight. She posed for pictures on the red carpet with hubby Kieran Hayler and her kids Princess, nine, and Junior, 11, whose dad is Katie's ex-husband Peter Andre.
Not at the event were Katie's son Harvey, 14, or her two children with Kieran: Jett, three, and Bunny, two.
Katie and Kieran, 29, are just back in the UK from a romantic beach holiday to Barbados, which Katie has branded a very belated honeymoon. (She married Kieran in January 2013.)
She revealed earlier this month she'd be taking a leave of absence from Loose Women to focus on her husband and children, starting with a holiday abroad with just Kieran.
Katie had explained how promoting her autobiography Reborn, meant the pain and trauma of Kieran's affair had resurfaced, and she needed to take time away from the spotlight to focus on herself and their family.
Kieran cheated on Katie with her best friend Jane Pountney. Katie discovered the affair in May 2015 while she was pregnant with the couple's second child. Although she initially vowed to divorce Kieran, she later decided to give him a second chance and stood by him as he entered therapy for sex addiction.
"We had therapy [after I found out about the affair] and I thought I was OK. But the past two weeks I've been on my book tour and it's opened up some wounds. It's been awful. I thought I'd dealt with it. But when I look back, I had just had babies and was concentrating on them and I was numb when it all happened.
"We've come two and a half years and Kieran is having to relive what kind of person he was, and I'm reliving it with a fresh mind, thinking, 'Oh my God, this is really what he did to me?'
"We are going to see a therapist to reassure us we're fine. It's horrible for both of us. I'm always like, 'it's fine' and move on to the next thing... It's a relief to me to admit I'm not as strong as people think. Enough is enough. I have to let my barriers down.
"I want to help Kieran through this as well. It's been tough on us both. It's been turbulent."