Colpomenia sinuosa, commonly named the oyster thief or sinuous ballweed, is a brown algae species in the genus Colpomenia.

It is the type species of its genus and is widespread in tropical to temperate zones around the world.

[6] This species is common in the intertidal and on reef flats, often growing on other algae or rocky substrates.

"Cryptic diversity and biogeography of the widespread brown alga Colpomenia sinuosa (Ectocarpales, Phaeophyceae)".

This Phaeophyceae (or brown alga) article is a stub.