The word cat derives from Old English catt, which belongs to a group of related words in European languages, including Welsh cath, Spanish gato, Basque katu, Byzantine Greek kátia, Old Irish cat, German Katze, and Old Church Slavonic kotka. The ultimate source of all these terms is Late Latin catus, cattus, catta "domestic cat", as opposed to feles "European wildcat".

It is unclear whether the Greek or the Latin came first, but they were undoubtedly borrowed from an Afro-Asiatic language akin to Nubian kadís and Berber kaddîska, both meaning "wildcat".