See text 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] According to the Interim Register of Marine and Nonmarine Genera,[1] and AlgaeBase (amount of species per genus):[3]