Gaius Asinius Quadratus was a Greek historian of Rome and Parthia of the third century. He was a senator who wrote a 15-book history of Rome, Chilieteris, which, according to the Suda, covered the period from the founding of Rome until the rule of Alexander Severus. He also wrote a Parthika in nine books, presumably a narrative of the Parthian campaigns of the preceding century. Some scholars attribute to him a Germanika, based on an excerpt preserved by Agathias, although this is debated.