Myronianus of Amastris (Μυρωνιανός ὁ Ἀμαστριανός) was a Greek author from the city of Amastris on the Black Sea coast. He is generally placed in the Roman imperial period, likely between the 1st and 3rd centuries CE. No details of his personal life or education survive.

His sole known work is the lost Historical Parallels (Ἱστορικαὶ Παραλλήλοι). It was a prose collection of biographical or historical comparisons, possibly arranged in paired accounts, and survives only through later citations.

Myronianus is significant as a source for later prominent writers. Plutarch cites him in the Life of Theseus, and Diogenes Laërtius uses him as a source for the philosopher Menedemus [1, 2]. These fragments show his work contained anecdotal material on historical and philosophical figures, placing him within a tradition of comparative biography and providing insight into the sources of major ancient authors.

Sources 1. Perseus Digital Library, "Plutarch, Theseus, section 32": http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A2008.01.0061%3Achapter%3D32 2. Perseus Digital Library, "Diogenes Laertius, Lives of Eminent Philosophers, Book 2, section 140": http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0258%3Abook%3D2%3Achapter%3D6