The cat (Felis catus), also known as the domestic cat or house cat to distinguish it from other felines, is a small carnivorous species of crepuscular mammal that is often valued by humans for its companionship and its ability to hunt vermin. It has been associated with humans for at least 9,500 years.

A skilled predator, the cat is known to hunt over 1,000 species for food. It is intelligent and can be trained to obey simple commands. Individual cats have also been known to learn on their own to manipulate simple mechanisms, such as doorknobs. Cats use a variety of vocalizations and types of body language for communication, including meowing, purring, hissing, growling, squeaking, chirping, clicking, and grunting. Cats are popular pets and are also bred and shown as registered pedigree pets. This hobby is known as the "Cat Fancy".

Until recently the cat was commonly believed to have been domesticated in ancient Egypt, where it was a cult animal. However a 2007 study found that all house cats are probably descended from a group of as few as five self-domesticating desert wildcats Felis silvestris lybica circa 8000 BC, in the Near East.

In 2004, a grave was excavated in Cyprus that contained the skeletons, laid close to one another, of both a human and a cat. The grave is estimated to be 9,500 years old, pushing back the earliest known feline-human association significantly.

In captivity, indoor cats typically live 14 to 20 years, though the oldest-known cat lived to age 36. Domesticated cats tend to live longer if they are not permitted to go outdoors (reducing the risk of injury from fights or accidents and exposure to diseases) and if they are neutered. Some such benefits are: castrated male cats cannot develop testicular cancer, spayed female cats cannot develop ovarian cancer, and both have a reduced risk of mammary cancer.

Like some other domesticated animals, cats live in a mutualistic arrangement with humans. It is believed that the benefit of removing rats and mice from humans' food stores outweighed the trouble of extending the protection of a human settlement to a formerly wild animal, almost certainly for humans who had adopted a farming economy. Unlike the dog, which also hunts and kills rodents, the cat does not eat grains, fruits, or vegetables.

In modern rural areas, farms often have dozens of semi-feral cats. Hunting in the barns and the fields, they kill and eat rodents that would otherwise spoil large parts of the grain crop. Many pet cats successfully hunt and kill rabbits, rodents, birds, lizards, frogs, fish, and large insects by instinct, but might not eat their prey. They may even present their kills, dead or maimed, to their humans, perhaps expecting to be praised or rewarded, or possibly even for the humans to complete the kill and eat the mouse.[citation needed]

In modern urban areas, some people find feral and free-roaming pet cats annoying and intrusive. Unaltered cats can engage in persistent nighttime calling (termed caterwauling) and defecation or "marking" of private property. Indoor confinement of pets and TNR programs for feral cats can help; some people also use cat deterrents to discourage cats from entering their property.