Marcus Fabius Quintilianus (c. 35 – c. 100) was a Roman rhetorician from Hispania, widely referred to in medieval schools of rhetoric and in Renaissance writing. In English translation, he is usually referred to as Quintilian, although the alternate spellings of Quintillian and Quinctilian are occasionally seen, the latter in older texts.

Quintilian was born ca. 35 in Calagurris (Calahorra, La Rioja) in Hispania. His father, a well-educated man, sent him to Rome to study rhetoric early in the reign of Nero. While there, he cultivated a relationship with Domitius Afer, who died in 59. "It had always been the custom … for young men with ambitions in public life to fix upon some older model of their ambition … and regard him as a mentor" (Kennedy, 16). Quintilian evidently adopted Afer as his model and listened to him speak and plead cases in the law courts. Afer has been characterized as a more austere, classical, Ciceronian speaker than those common at the time of Seneca, and he may have inspired Quintilian’s love of Cicero.