Euplectella cucumer is a species of glass sponge in the family Euplectellidae. It has been found around the Seychelles.
The generic name, Euplectella, is derived from the Latin , meaning "to weave", and the prefix eu-, in reference to the "complexity of the interweaving of its component threads".
The specific epithet, cucumer, is derived from the Latin , meaning "cucumber", due to the fact that the shape of the species' body resembles a cucumber.