Diogenes of Cyzicus (Διογένης ὁ Κυζικηνός) was a Greek historian from the city of Cyzicus in Mysia. He is chronologically placed in the 4th century BCE based on the content of his work, which treated events of the late 5th and early 4th centuries BCE [1]. No other biographical details survive.

His sole known work is the Persica (Περσικά), a history of Persia in five books [1][2]. The work is lost and survives only in a small number of fragments.

Diogenes represents a minor figure within the tradition of Persica, the Greek historiographical genre on Persian history. His fragments, preserved by later compilers, illustrate the continuation of local Ionian historiography into the Classical and early Hellenistic periods [1][2].

Sources 1. Perseus Digital Library, "Diogenes of Cyzicus" in The Oxford Classical Dictionary (via Perseus Hopper): https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0063:entry=diogenes-of-cyzicus-harpers 2. ToposText, "Diogenes of Cyzicus" (Fragmentary Greek Historians): https://topostext.org/people/1410