Callithamniaceae is a family of red algae (Rhodophyta) in the order Ceramiales.[1] The family was first described by Friedrich Traugott Kützing in 1843.[2][3]
Algae in the family Callithamniaceae have filamentous fronds with branches arranged in two rows on opposite sides of a stem and in the same plane, or radially or in whorls. In the female gametophytes, the procarps are four-celled and there are no sterile cells.[3]