Caulerpa trifaria is a species of seaweed in the Caulerpaceae family.

[1] The seaweed has a slender stolon and green fronds that typically grow to 5 to 25 centimetres (2.0 to 9.8 in) in height with a width of 4 to 12 millimetres (0.16 to 0.47 in).

[1] The species is usually found in calm sheltered waters at depths of 2 to 30 metres (7 to 98 ft).

In Western Australia, it is found along the coast around Perth extending south to around Esperance.

[1] It is also found in Victoria and Tasmania.