Archemachus of Euboea was a Hellenistic historian from Euboea, active in the late 4th or early 3rd century BCE. He is known only through citations by later authors such as Athenaeus and Stephanus of Byzantium. His work belongs to the genre of local historiography, which documented regional myths, legends, and history.

His sole known work, the Euboica or On Euboea, is now lost. It survives only in fragments preserved for their antiquarian and etymological content. This prose work focused on the island’s early settlements, customs, and notable figures.

Archemachus is significant as a representative of early Hellenistic local history. His Euboica served as an important source for Euboean traditions, and its fragments contributed to preserving local lore within the broader stream of Greek historiography.