Legio I Pontica: one of the legions of the later Roman empire. Its name means "the legion of the Black Sea".
This legion was created by the emperor Diocletian (284-305) to defend the newly created province Pontus Polemoniacus, which corresponds to the southeastern shores of the Black Sea. Because this province already existed in 297, we may assume that the roots of the legion go back to the first decade of Diocletian's reign. The legion was stationed at Trapezus (modern Trabzon), which had once been guarded by XV Apollinaris.
I Pontica is mentioned in a dedication to Diocletian and his fellow emperors that can be dated to 297-305 (CIL 3.6746; here). It was still in Trapezus when the Notitia Dignitatum was composed, an early fifth-century list of Roman magistracies and military units.