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

This species can be found along the southern North Island, the South Island, Chatham Island, Stewart Island, Snares Island of New Zealand.

[1] It is also found along the coast in a large area extending from near Karratha in the northern Pilbara region to east of Esperance in the Goldfields-Esperance region of Western Australia.

[2]