Sir Richard of Cornwall (died 1296) was an illegitimate son of Richard, 1st Earl of Cornwall (1209–1272) (the second son of King John (1199–1216)) by his mistress Joan de Valletort.
He was the second illegitimate son of Richard, 1st Earl of Cornwall (1209–1272), the second son of King John (1199–1216).
His mother was Richard's mistress Joan, of unknown origins. She married twice:
Sir Richard of Cornwall received a grant from his half-brother Edmund, 2nd Earl of Cornwall (died 1300) in which he was called "brother".
He married Joan FitzAlan, daughter of John FitzAlan, 6th Earl of Arundel, and by her had three sons and a daughter, including:
He adopted the arms of his father with difference a bordure engrailed. These arms were later used by the following families which claimed descent from him:
He was slain by an arrow at the Siege of Berwick in 1296.