Publius Herennius Dexippus was a third-century CE Athenian historian, statesman, and military commander from a prominent family. He held high civic and religious offices in Athens and is famed for organizing a local defense force that harassed and helped repel a Herulian invasion around 267 or 268 CE. His career and writings responded directly to the profound military and political crises of the Roman Empire during this period.

His major work, the Scythica, was a history in at least twelve books covering events from the death of Alexander the Great to the Gothic and Herulian invasions of the 260s CE; substantial fragments survive. He also composed a universal Chronicle and a chronological Syntagma, both now lost except for minor references.

Dexippus is a pivotal contemporary source for the third-century Gothic Wars. His classicizing, Thucydidean style marks him as the last major historian in the classical Greek tradition before the Byzantine era, providing crucial insight into how a Greek aristocrat perceived the fragmentation of the empire.