Jania is a genus of red seaweeds with hard, calcareous, branching skeletons in the family Corallinaceae. Members of the genus are found in sheltered reef habitats, often in crevices or other shaded areas.
Members of the genus are dichotomously branched and grow in wide, tangled clumps. The branches are composed of stiff, cylindrical segments and can bend at the joints. The colour is generally red or pink and the joints are white.
The World Register of Marine Species list the following: