Caulerpa trifaria is a species of seaweed in the Caulerpaceae family.
The seaweed has a slender stolon and green fronds that typically grow to 5to in height with a width of 4to.
The species is usually found in calm sheltered waters at depths of 2to. In Western Australia, it is found along the coast around Perth extending south to around Esperance. It is also found in Victoria and Tasmania.