Odiellus spinosus is a species of harvestmen in the family Phalangiidae.
Odiellus spinosus can reach a body length of in males, of in females. This harvestmen shows three large, almost flat spines (hence the species name) in front of the eyes and a black-edged saddle on the back. Moreover the abdomen is distinctly flattened, with some rows of brown spots across each tergite.
Adults can be found from June and until December.