Bors (/ˈbɔːrz/; French: Bohort) is the name of two knights in the Arthurian legend, a father and a son. They are both introduced in the 13th-century Lancelot-Grail romance prose cycle.

King Bors (Bohors, Boho[o/u]rt, Bo[o]rt, Bordo, Borz) is the ruler of Ganis (Gannes, Ganys, Gaun[n]es, Gaynes, Gaynys) during the early period of King Arthur's reign. His brother, King Ban of Benoic, is the father of Lancelot. Bors' two sons, one also named Bors and the other named Lionel, later both join Arthur's Round Table as prominent members.

The younger Bors, known as Sir Bors (Bohors, Bohort li Escillies, Bohortes, Bo[o]rdo, Boors, Bo[o]rt, Borz, Bours, Bwrt) and by his epithet de Ganis (and other spellings), becomes one of the best Knights of the Round Table and participates in the achievement of the Holy Grail. His own son is Elyan the White, also a member of the Round Table.

The elder Bors is the king of Ganis in Brittany. He is brother of King Ban and uncle of Hector de Maris and Lancelot. He marries Evaine, the sister of Ban's wife Elaine, and they have two sons, Bors and Lionel.

Ban and Bors become King Arthur's valuable early allies in his war against eleven rebel kings in Great Britain, including Lot, Urien, and Caradoc. In return, Arthur vows to help them against their Frankish enemy, King Claudas, who has been threatening their lands back in the continent. Arthur is late on his promise, though, and Claudas succeeds in his invasion, resulting in both kings' deaths. Ban's son Lancelot is taken by the Lady of the Lake, but Bors' children are raised in captivity by Claudas' retainers.

Bors de Ganis and Lionel live for several years at Claudas' court, but they eventually rebel against him and even slay his cruel son Dorin. Before Claudas can retaliate, the boys are rescued by a servant of the Lady of the Lake and are spirited off to be raised with their cousin Lancelot. They all grow up to be excellent knights and go to Camelot to join King Arthur's retinue. Bors is recognisable by a distinctive scar on his forehead, and participates in most of the King's conflicts, including the eventual battle with Claudas which liberates his father's lands. Bors fathers Elyan the White when the beautiful daughter of King Brandegoris, Claire, tricks him into sleeping with her by way of a magic ring; he later introduces his son into the Round Table.

Sir Bors is always portrayed as one of the Round Table's finest, but his real glory comes on the Grail Quest, where he proves himself worthy enough to witness the Grail's mysteries alongside Galahad and Percival. Several episodes display his virtuous character; in one, a lady approaches Bors vowing to commit suicide unless he sleeps with her. He refuses to break his vow of celibacy; the lady and her maidens threaten to throw themselves off the castle battlements. As the ladies jump off, they reveal themselves to be demons set on deceiving him by playing to his sense of compassion. In another, Bors faces a dilemma where he must choose between rescuing his brother Lionel, being whipped with thorns by villains in one direction, and saving a young girl who has been abducted by a rogue knight in the other. Bors chooses to help the maiden, but prays for his brother's safety. Lionel escapes his tormentors and tries to murder Bors, and Bors does not defend himself, refusing to raise a weapon against his kinsman. Fellow Knight of the Round Table Calogrenant and a hermit try to intervene, but Lionel slays them both when they get in the way. Before he can kill his brother, however, God strikes him down with an immobilising column of fire. Bors, Galahad, and Percival go on to achieve the Holy Grail and accompany it to Sarras, a mystical island in the Holy Land, where then Galahad and Percival pass away while there. Bors is the only one to return, and the text of the Vulgate Queste is presented as a purported written record of Bors telling the full story of the quest back in Camelot. His role as both the hero and narrator of the story mirrors that of Merlin in an earlier part of the Vulgate Cycle.

At the end of the entire Vulgate Cycle, Bors further ultimately emerges as a successor to Arthur, ruling after the King's (assumed) death. Both there and in the Post-Vulgate Cycle, Mordred's elder son mortally wounds Lionel. Bors kills him with one blow, avenging his brother.