The `Bleeding Love` hitmaker was left terrified when the feline jumped on her leg and started viciously scratching her.
The animal then refused to let go and dug its claws in deeper when the frightened singer tried to shake it off.
Leona, 25, said: "A cat jumped on me the other week.
"They scare me. It hissed and scratched my legs - I didn`t know what to do!"
She added to Britain`s Daily Mirror newspaper: "So I got up and shook my leg, but she was stuck to it. It was an evil cat. I don`t like evil cats."
Despite the incident, the pop star is known to be a huge animal lover.
She is a public supporter of PETA (People for the Ethical Treatment of Animals) and a vegetarian.
Leona also refuses to wear suede, leather or any other animal products and is a committed campaigner for several animal charities and devotes a lot of her time and energy to the WSPA - World Society for the Protection of Animals - because they "campaign to change laws to stop the cruel treatment of animals".