The grass porgy (Calamus arctifrons) is a species of ray-finned fish in the family Sparidae. It is endemic to the northeastern Gulf of Mexico and occurs in shallow coastal waters in seagrass beds.

Taxonomy Calamus arctifrons was first described by George Brown Goode and Tarleton Hoffman Bean in 1882. The species name, arctifrons translates to "contracted forehead".

Description Grass porgies exhibit a steep forehead and large mouth with a heavy lower jaw. The body has 7 or 8 vertical dark bands that extend into the fins. They typically reach lengths of up to 25 cm (10 in). Grass porgies are native to the northeastern Gulf of Mexico. They prefer waters shallower than 30 m in depth. They are most common in waters off Florida but occasionally stray as far west as Louisiana and south into the West Indies.