Hecataeus of Miletus (c. 550 BCE – c. 476 BCE), named after the Greek goddess Hecate, is an early Greek historian of a wealthy family.

He flourishes during the time of the Persian invasion.

After having traveled extensively, he settles in his native city, where he occupies a high position, and devotes his time to the composition of geographical and historical works.

When Aristagoras holds a council of the leading Ionians at Miletus to organize a revolt against the Persian rule, Hecataeus in vain tries to dissuade his countrymen from the undertaking.

In 494 BCE, when the defeated Ionians are obliged to sue for terms, he is one of the ambassadors to the Persian satrap Artaphernes, whom he persuades to restore the constitution of the Ionic cities.

Hecataeus is the first known Greek historian, and is one of the first classical writers to mention the Celtic people.