A feral cat is a descendant of a domesticated cat that has returned to the wild. It is distinguished from a stray cat, which is a pet cat that has been lost or abandoned, while feral cats are born in the wild; the offspring of a stray cat can be considered feral if born in the wild.

In many parts of the world, feral cats are descendants of domestic cats that were left behind by travelers. Because cats are not native to all parts of the world, feral cats can cause harm to local environments by preying on local species. This is especially true on islands where feral cats have sometimes had a substantial and deleterious effect on the local fauna.