Characidium grajahuense is a fish in the family Crenuchidae.

[1] It is native to South America and is found in the coastal streams between Guanabara Bay and the Mangaratiba, in Rio de Janeiro, Brazil.

[1] This species reaches a length of 8.8 cm (3.5 in).

[1] The fishes name in denoting place: Grajaú, Rio de Janeiro, Brazil, which is the type locality.

This Characiformes-related article is a stub.