Gaius Licinius Mucianus (fl. 1st century AD) was a general, statesman, and writer of ancient Rome.

His name shows that he had passed by adoption from the Mucian to the Licinian gens. About 55 AD he was sent by Claudius, who had become suspicious of his intimacy with Messallina, to Armenia with Domitius Corbulo. Under Nero he regained the imperial favor, and is recorded as suffect consul ca. 65.

After the death of Galba (69), Mucianus and Vespasian (who was at the time in Judaea) both swore allegiance to Otho, but when the civil war broke out Mucianus persuaded Vespasian to take up arms against Vitellius, who had seized the throne. It was agreed that Vespasian should stay behind to settle affairs in the East, while Mucianus made his way through Asia Minor and Thrace to attack Vitellius. He reached Rome the day after the death of Vitellius, and found Domitian, Vespasian's son, at the head of affairs, but until the arrival of Vespasian the real master of Rome was Mucianus. But he never wavered in his allegiance to Vespasian, whose favor he retained in spite of his arrogance. He is mentioned as suffect consul in 70 and 72. As no mention is made of Mucianus during the reigns of Titus or Domitian, he probably died during the reign of Vespasian.

He was a clever writer and historian. He made a collection of the speeches and letters of the Romans of the older republican period, probably including a corpus of proceedings of the senate (A eta senatus), and was the author of a work, chiefly dealing with the natural history and geography of the East, which is often quoted by Pliny as an authority, especially for fabulous statements.

See monograph by L. Brunn (Leipzig, 1870).

This article incorporates text from the public domain 1911 Encyclopædia Britannica.