Ursicinus was a senior military officer, holding the rank of "master of cavalry" (magister equitum) in the later Roman Empire c. 349–359.
In AD 351 or 352 he was entrusted with the suppression of the Jewish revolt against Caesar Constantius Gallus. Tiberias and Diospolis, two of the cities conquered by the rebels, were almost completely destroyed, while Diocaesarea was razed to the ground. Ursicinus also was ordered to kill several thousand rebels, even young ones.
In 353, historian Ammianus Marcellinus was attached to the command of Ursicinus at his headquarters in Nisibis, where he remained until recalled in 354 by Gallus to take part in an investigation of treason in Antioch.
When, in 355, Claudius Silvanus revolted against Emperor Constantius II in Gaul, Ursicinus was sent to him with a letter of recall by Constantius. However, Ursicinus had Silvanus killed and assumed his command.
Ursicinus was dismissed after the destruction of Amida (modern Diyarbakır, Turkey) in AD 359 by the Persians, for which he was officially blamed.
The Roman historian Ammianus Marcellinus revered Ursicinus, and his account is greatly biased in his favour.
Apparently, Ursicinus was married at some point, as he had a son named Potentius. While serving as a tribune (regimental commander), he was killed at the Battle of Adrianople in 378.