Kat Harley was born and raised in Poznan, Poland. Her father, Piotr Dlubala, was a carpenter, and her mother, Barbara Breiter, was an architect. She came to the United States in September 1989. Kat's first husband died in 2000, while her brief second marriage ended in divorce in 2004. As a teenager, Kat was first featured in a Polish TV movie, _Powrót do Polski .
