Helvidius Priscus (died c. 70–79 ce) was a Roman Stoic who forcefully upheld the principle that the emperor should act only with the consent of the Senate.
Though the son of a centurion, he rose to the Senate in the reign of Nero and became praetor in 70 ce. Later his uncompromising freedom of speech brought him into conflict with the emperor Vespasian, perhaps because he opposed dynastic succession, and he was put to death.