Monoplex mundus is a species of predatory sea snail, a marine gastropod mollusk in the family Cymatiidae.
This marine species occurs in the Gulf of Mexico and in the Indian Ocean off the Mascarene Basin.
The maximum recorded shell length is 38 mm. The species was discovered in 1849 by A. Gould. It was originally classified as Triton mundum.
Minimum recorded depth is 149 m. Maximum recorded depth is 185 m.