Tetrastemma

{{Short description|Genus of ribbon worms}}

{{Automatic taxobox

|image = Tetrastemma_(YPM_IZ_101767)_003.jpeg

|image_caption =Preserved specimen of Tetrastemma

|taxon = Tetrastemma

|authority = Ehrenberg, 1831

}}

Tetrastemma is a genus of nemerteans belonging to the family Tetrastemmatidae.{{cite web |title=Tetrastemma Ehrenberg, 1831 |url=https://www.gbif.org/species/2506446 |website=www.gbif.org |access-date=4 July 2021 |language=en}}

The genus has cosmopolitan distribution.