The Venus girdle (Cestum veneris) is a comb jelly in the family Cestidae. It is the only member of its genus, Cestum, and is also the largest of all known ctenophores.

Venus girdles resemble transparent ribbons with iridescent edges. They may grow up to a metre in total length. Canals run the length of the ribbon in which bioluminescence activates when disturbed.

This species is pelagic and is found in tropical and subtropical oceans worldwide in midwater.

These animals swim horizontally using muscular contractions as well as the beating of the comb rows. The oral edge leads. They eat small crustaceans.