Magnus the Historian is an obscure figure dated to the 5th–6th century CE. No biographical details exist in standard scholarly references, and the name itself, common in the Late Roman Empire, is unattested among known historians of that era like Procopius or Agathias.

He is credited with a single historical work in prose Koine Greek, but its title, content, and subject matter are unknown. The work is presumed lost, with no fragments cataloged in major digital collections.

His significance remains indeterminable. He is absent from accounts of late antique Greek historiography, and any potential importance would depend entirely on the unknown nature of his lost writing.