Publius Herennius Dexippus (c. AD 210-273), Greek historian, statesman and general, was an hereditary priest of the Eleusinian family of the Kerykes, and held the offices of archon basileus and eponymus in Athens.

When the Heruli overran Greece and captured Athens (269), Dexippus showed great personal courage and revived the spirit of patriotism among his degenerate fellow-countrymen. A statue was set up in his honour, the base of which, with an inscription recording his services, has been preserved (Corpus Inscr. Atticarum, iii. No. 716). It is remarkable that the inscription is silent as to his military achievements. Photius (cod. 82) mentions three historical works by Dexippus, of which considerable fragments remain:

1. an epitome of a work by Arrian
2. a history of the wars of Rome with the Goths (or Scythians) in the 3rd century
3. a chronological history from the earliest times to the emperor Claudius Gothicus (270), frequently referred to by the writers of the Augustan history. The work was continued by Eunapius of Sardis down to 404.

Photius speaks very highly of the style of Dexippus, whom he places on a level with Thucydides, an opinion by no means confirmed by the fragments.