thumb|300px|[[Legionary denarii (Mark Antony)|Denarius minted by Mark Antony to pay his legions. On the reverse, the aquila of his Third legion.]]
thumb|Roman re-enactors portraying Legio III Cyrenaica.
Legio III Cyrenaica, ( Third Legion "Cyrenean") was a legion of the Imperial Roman army. The legion had its origins among the forces of Mark Antony during the civil wars of late first century BC. In the Imperial period it was stationed in Egypt, where it played a key role in campaigns against the Nubians and Jews. In the first century AD, it was usually located in Arabia Petraea. There are still records of the legion in Syria at the beginning of the 5th century. The legion symbol is unknown.
History
Origins and service in Egypt
The origins of the legion are unclear, but it is first attested as part of Mark Antony's forces during the period of the Second Triumvirate (43-33 BC). Cyrenaica was under the control of Marcus Aemilius Lepidus before 36 BC and of Mark Antony after that date; either of them might have established the Legio III. Pollard and Berry suggest that the legion was established by Lucius Pinarius Scarpus, an ally of Mark Antony who was his governor of Cyrenaica in the 30s BC. The legio III is one of the many legions that appear in Mark Antony's Legionary denarii produced in 32-31 BC.
After Augustus defeated Antony at the Battle of Actium in 30 BC and annexed Egypt, he used the legion to occupy Thebes, the main centre in Upper Egypt.