Percival (/ˈpɜːrsɪvəl/, also written Perceval, Parzival, Parsifal), alternatively called Peredur (Welsh pronunciation: [pɛˈrɛdɨr]), is a figure in the legend of King Arthur, often appearing as one of the Knights of the Round Table.

A comparable list in the last pages of The Dream of Rhonabwy refers to a Peredur Paladr Hir ("of the Long Spear-Shaft"), whom Peter Bartrum identifies as the same figure.

[8][5] This may represent an epithet that denoted a local association, possibly pointing to Eliffer's son as the prototype, but which came to be understood and used as a patronymic in the Welsh Arthurian tales.

[10] In all of his appearances, Chrétien de Troyes identifies Perceval as "the Welshman" (li Galois), indicating that, even if he does not originate in Celtic tradition, he alludes to it.

[3] Groos and Lacy argue that, "even though there may have been a pre-existing 'Perceval prototype,' Chrétien was primarily responsible [...] for the creation of [one of] the most fascinating, complex, and productive characters in Arthurian fiction".

[14] Perlesvaus etymologizes the name (there: Pellesvax) as meaning "He Who Has Lost The Vales", referring to the loss of land by his father, while also saying Perceval called himself Par-lui-fet (made by himself).

[15] Richard Wagner followed a discredited etymology proposed by journalist and historian Joseph Görres that the name derived from Arabic fal parsi (pure fool) when choosing the spelling "Parsifal" for the figure in his opera.

The young knight does not ask about significance of these items and proceeds to further adventure, including a stay with the Nine Witches and the encounter with the woman who was to be his true love, Angharad.

[17] Goetinck sees in Peredur a variant on the Celtic theme of the sovereignty goddess, who personifies the country and has to be won sexually by the rightful king or heir to secure peace and prosperity for the kingdom.

In Robert de Boron's account, he is of noble birth, and his father is variably stated to be either Alain le Gros, King Pellinore, or another worthy knight.

In the tales in which he is Pellinore's son, his brothers include Aglovale, Lamorak and Dornar, as well as a half-brother named Tor by his father's affair with a peasant woman.

In the later accounts of Arthurian prose cycles, and consequently Thomas Malory's Le Morte d'Arthur, the true Grail hero is Galahad, the son of Lancelot, but, though his role in the romances is diminished, Percival remains a major character and is one of only two knights (the other is Bors) who accompany Galahad to the Grail castle and complete the quest with him.