Theophilus or Theophilos was a historian and geographer, if at least the passages about to be quoted refer to one and the same person. He is mentioned by Josephus

Josephus

Titus Flavius Josephus , also called Joseph ben Matityahu , was a 1st-century Romano-Jewish historian and hagiographer of priestly and royal ancestry who recorded Jewish history, with special emphasis on the 1st century AD and the First Jewish–Roman War, which resulted in the Destruction of...

 (c. Apion. i. 23) among those writers, who had noticed the Jews

Jews

The Jews , also known as the Jewish people, are a nation and ethnoreligious group originating in the Israelites or Hebrews of the Ancient Near East. The Jewish ethnicity, nationality, and religion are strongly interrelated, as Judaism is the traditional faith of the Jewish nation...

. The third book of his work on Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 , and the second of that on the Peloponnesus, are quoted by Plutarch

Plutarch

Plutarch then named, on his becoming a Roman citizen, Lucius Mestrius Plutarchus , c. 46 – 120 AD, was a Greek historian, biographer, essayist, and Middle Platonist known primarily for his Parallel Lives and Moralia...

 (Parallela Minora, 13, 32, pp. 309, a., 313, d). Ptolemy

Ptolemy

Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

 (Geogr. i. 9. § 3) quotes a statement from some geographical work by Theophilus, the title of which he does not mention, but which is no doubt the same as the , the eleventh book of which is referred to by Stephanus of Byzantium

Stephanus of Byzantium

Stephen of Byzantium, also known as Stephanus Byzantinus , was the author of an important geographical dictionary entitled Ethnica...

 (s. v. . Plutarch

Plutarch

Plutarch then named, on his becoming a Roman citizen, Lucius Mestrius Plutarchus , c. 46 – 120 AD, was a Greek historian, biographer, essayist, and Middle Platonist known primarily for his Parallel Lives and Moralia...

also (de Fluv. 24) cites the first book of a work of Theophilus. (Vossius, de Hist. Graec. p. 504, ed. Westermann.)