Raphidocelis is a genus of green algae in the family Selenastraceae.

[3] One species, Raphidocelis subcapitata, is a common model organism in the field of toxicology, where it is used as a bioassay.

It was previously known as Selenastrum capricornutum, a name later shown to be incorrect.

[3] Raphidocelis is sometimes reported as lacking a pyrenoid; it does indeed contain one, although it is not covered in layer of starch grains making it often difficult to observe under the light microscope.

[4] Raphidocelis reproduces asexually by autospores; zoospores and sexual reproduction have not been observed in this genus.