Possibly from Celtic 'artos' meaning 'bear,' famously borne by the legendary King Arthur.
Arthur is one of those names whose power comes partly from mystery. It is usually linked to Celtic and Brittonic roots, and many scholars connect it to the Welsh name Arthwr. The first element may relate to arth, meaning “bear,” which gave the name an early aura of strength and kingship, though other theories tie it to a Roman family name, Artorius.
That uncertainty has only deepened the name’s legend: Arthur feels as if it stands at the meeting point of the ancient Celtic world and the Latin-speaking world that surrounded it. Its great cultural engine, of course, is King Arthur. Whether or not a single historical Arthur ever lived, the medieval Arthur of Geoffrey of Monmouth, Chrétien de Troyes, and later Malory became one of the central figures of European imagination.
Around him grew Camelot, Excalibur, Merlin, Guinevere, and the Round Table, so the name came to signify not just bravery but ideal kingship, chivalry, and tragic grandeur. Later bearers such as Arthur Conan Doyle and Arthur Miller gave the name literary weight of a different sort: intelligent, serious, and unmistakably classic. Arthur’s style has shifted over time without ever quite disappearing.
In English-speaking countries it was solidly respectable in the Victorian era, then for a while felt grandfatherly, even quaint. In recent decades it has returned as part of the revival of antique, sturdy names with storybook depth. Today Arthur can sound scholarly, noble, and warm all at once, helped by affectionate short forms like Art and Artie. Few names carry such a dense cargo of myth, history, and emotional resonance.