Theophilus Protospatharius (Greek: Θεόφιλος Πρωτοσπαθάριος; ca. 7th century) was the author of several extant Greek medical works of uncertain status, either from Philaretus or Philotheus. Nothing is known of his life or the time when he lived. He is generally called "Protospatharius", which seems to have been originally a military title given to the colonel of the bodyguards of the emperor of Constantinople (Spatharioi); but which afterwards became also a , or was associated with the government of provinces and the functions of a judge.
It is conjectured that he lived in the 7th century; that he was the tutor to Stephanus Atheniensis; that he arrived at high professional and political rank; and that at last he embraced the monastic life. All this is, however, quite uncertain; and with respect to his date, it has been supposed that some of the words which he uses belong to a later period than the seventh century; so that he may possibly be the same person who is addressed by the title "Protospatharius " by Photius, in the ninth. He appears to have embraced in some degree the Peripatetic philosophy; but he was certainly a Christian, and expresses himself on all possible occasions like a man of great piety: in his physiological work especially he everywhere points out with admiration the wisdom, power, and goodness of God as displayed in the formation of the human body.
Five works are attributed to him: