Platyceras is a genus of extinct Paleozoic sea snails, marine gastropod mollusks in the family Platyceratidae.

This genus is known from the Silurian to the Middle Triassic periods and especially abundant in the Devonian and Carboniferous.

The posterior portion of the shell, at the apex, is usually slightly coiled in an asymmetrical fashion.

Frequently, the front portions of the shells are broken, though the posterior sections are relatively well preserved.

[1] Platyceras and other platyceratid gastropods are known for the complex symbiotic relationships they had with crinoids.