An American woman has been ringing Katona "non-stop for weeks" and recently contacted the Celebrity Big Brother star's manager Max Clifford claiming to have watched her getting changed at her Surrey mansion.
"I was getting dressed and there was a phone call to Max's company from this lady saying she'd been watching me getting changed," Katona told the Sunday Mirror. "The thing was I had been naked and putting my clothes on minutes before.
"So I panicked and called the police. But this woman has been annoying us all for weeks now. At the end of the day I've got four kids, live in a big house and have to take this sort of thing seriously.
"This is the first time I've felt genuinely scared about a stalker. I won't let this beat me though. I'm finally getting my life on track and nothing is going to stand in my way."
Clifford described the situation as "very sad for the lady" and "very scary for Kerry".
Katona was previously the victim of a stalker in December 2009, when a fan began turning up at her Cheshire mansion after they became Facebook friends. The fan later received a warning to stay away from Katona.
She recently announced that she has fallen in love with artist Steve Alce after meeting him at a charity dinner in October.