Arthur \a-rthur, ar-thur\ as a boy's name is pronounced AR-ther. It is of Celtic origin. King Arthur of Britain (sixth century) and his Round Table of knights have become legendary figures. His name was first found in the Latin form Artorius, which is of obscure origin. Other possible sources include "artos", the Celtic word for "bear"; an Irish Gaelic word meaning "stone"; Arnthor, an Old German name meaning "Thor, the eagle". Often used in the Middle Ages, but uncommon until the early 19th century, when Arthur Wellesley, the Duke of Wellington, vanquished Napoleon. Tennyson's "Idylls of the King" (19th century) and the Victorian romanticism of things medieval in general and of Arthurian legend in particular promoted its use. Arturo is the Italian and Spanish form; Arto and Arrturi are Finnish. Columnist Art Buchwald; actor Art Carney; tennis celebrity Arthur Ashe; writer Arthur C. Clarke; playwright Arthur Miller.

Arthur has 17 variant forms: Aart, Arrt, Art, Artair, Arte, Arther, Arthor, Arthuro, Artie, Arto, Artor, Artro, Artturi, Artur, Arturo, Artus and Arty.

For more information, see also the related name Arthel.