Theodore Stratelates (Ancient Greek: Ἅγιος Θεόδωρος ὁ Στρατηλάτης, transl. 'the General' or 'Military Commander'; Coptic: ⲡⲓⲁⲅⲓⲟⲥ Ⲑⲉⲟⲇⲱⲣⲟⲥ), also known as Theodore of Heraclea (Ancient Greek: Θεόδωρος Ἡρακλείας; AD 281–319) or Theodore of Arabia, was a martyr and warrior saint in the Eastern Orthodox, Catholic and Oriental Orthodox Churches.

There is much confusion as to whether he and St. Theodore of Amasea were the same person, as the stories about their lives later diverged into two separate traditions.

Of Greek origin, Theodore was born in the city of Euchaita in Asia Minor. He killed a giant serpent living on a precipice in the outskirts of Euchaita. The serpent had terrorised the countryside. Theodore armed himself with a sword and vanquished it. According to some of the legends, because of his bravery, Theodore was appointed military-commander (stratelates) in the city of Heraclea Pontica, during the time the emperor Licinius (307–324) began a fierce persecution of Christians. Theodore invited Licinius to Heraclea, having promised to offer a sacrifice to the pagan gods. He requested that all the gold and silver statues of the gods which they had in Heraclea be gathered up at his house. Theodore then smashed them into pieces which he then distributed to the poor.

Theodore was arrested and subjected to torture and crucified. His servant Varos (also venerated as a saint), witnessed this and recorded it. In the morning the imperial soldiers found him alive and unharmed. Not wanting to flee a martyr's death, Theodore voluntarily surrendered to Licinius, and was beheaded by the sword. This occurred on 8 February 319, on a Saturday, at the third hour of the day. His "life" is listed in Bibliotecha Hagiographica Graeca 1750-1754.

Numerous conflicting legends grew up about the life and martyrdom of Theodore of Amasea so that, in order to bring some consistency into the stories, it seems to have been assumed that there were two different venerated individuals, St Theodore Tiron of Amasea and Theodore Stratelates of Heraclea. The earliest text referring to the two saints is the Laudatio of Niketas David of Paphlagonia in the 9th century. It was said that his Christianity led to many conversions in the Roman army, which was the reason that Licinius was so concerned. Christopher Walter treats at length of the relationship between these saints.

It is suggested that Theodore Tiron as a recruit and ordinary foot soldier was viewed by the people of Byzantium as a patron of common soldiers and that the military aristocracy sought a patron of their own rank.

Another possibility is that he was in fact originally derived from a third Theodore called Theodore Orientalis from Anatolia.

In art both Theodore of Amasea and Theodore Stratelates are shown with thick black hair and pointed beards. In older works they were often distinguished by the beard having one point for Theodore Tiron of Amasea and two points for Stratelates as in the fresco from the Zemen Monastery below.