The domestic cat (Latin: Felis catus) or the feral cat (Latin: Felis silvestris catus) is a small, typically furry, carnivorous mammal. They are often called house cats when kept as indoor pets or simply cats when there is no need to distinguish them from other felids and felines. Cats are often valued by humans for companionship and for their ability to hunt vermin. There are more than 70 cat breeds; different associations proclaim different numbers according to their standards.

Cats are similar in anatomy to the other felids, with a strong, flexible body, quick reflexes, sharp retractable claws, and teeth adapted to killing small prey. Cat senses fit a crepuscular and predatory ecological niche. Cats can hear sounds too faint or too high in frequency for human ears, such as those made by mice and other small animals. They can see in near darkness. Like most other mammals, cats have poorer color vision and a better sense of smell than humans. Cats, despite being solitary hunters, are a social species and cat communication includes the use of a variety of vocalizations (mewing, purring, trilling, hissing, growling, and grunting), as well as cat pheromones and types of cat-specific body language.

Cats have a high breeding rate. Under controlled breeding, they can be bred and shown as registered pedigree pets, a hobby known as cat fancy. Failure to control the breeding of pet cats by neutering and the abandonment of former household pets has resulted in large numbers of feral cats worldwide, requiring population control. This has contributed, along with habitat destruction and other factors, to the extinction of many bird species. Cats have been known to extirpate a bird species within specific regions and may have contributed to the extinction of isolated island populations. Cats are thought to be primarily, though not solely, responsible for the extinction of 33 species of birds, and the presence of feral and free ranging cats makes some locations unsuitable for attempted species reintroduction in otherwise suitable locations.

Since cats were venerated in ancient Egypt, they were commonly believed to have been domesticated there, but there may have been instances of domestication as early as the Neolithic from around 9,500 years ago (7,500 BCE). A genetic study in 2007 concluded that domestic cats are descended from Near Eastern wildcats, having diverged around 8,000 BCE in West Asia. A 2016 study found that leopard cats were undergoing domestication independently in China around 5,500 BCE, though this line of partially domesticated cats leaves no trace in the domesticated populations of today.

As of a 2007 study, cats are the second most popular pet in the United States by number of pets owned, behind the first, which is freshwater fish.