Ergias of Rhodes was a Greek historian who lived during the 4th century BCE. No biographical details of his life are preserved, and his existence is attested solely through later citations.

His only known work is a history of Rhodes, preserved in fragments. Later authors such as Athenaeus cite it, often referencing Rhodian mythological and early historical traditions. Its exact ancient title is lost, though modern scholarship typically refers to it as The History of Rhodes.

Ergias is a significant source for local Rhodian history and foundation myths. His fragments represent the genre of local history, known as horography, and provide valuable evidence for the regional traditions used by later compilers.