In the legends derived from the chansons de geste Bayard was a magic bay horse, renowned for his spirit, and who possessed the supernatural ability to adjust his size to his riders. "Bayard" is the French form; in Italian he is known as Baiardo.

Bayard first appears as the property of Renaud, also known as Rinaldo, in the twelfth century Chanson de Renaud de Montauban. The horse was capable of carrying Rinaldo and his three brothers, les quatre fils Aymon ("the four sons of Aymon") all at the same time. In the poem, Charlemagne is angered at Renaud, and orders him to be banished, and the horse to be slain by being cast into a river with a millstone around its neck. Bayard survives the ordeal, and after other adventures is reunited with Renaud. Bayard also appears in the epic poems on chivalrous subjects by Ludovico Ariosto and Torquato Tasso.

Outside the city of Dinant in Belgium stands the "Bayard rock", a large cleft rock formation that was said to have been split by Bayard's mighty hooves.

Bayard can also refer to:

• Pierre Terrail, seigneur de Bayard