Cryptocheilus is a genus of spider wasps of the subfamily Pepsinae, they are found in the world's warmer regions. They vary in size from medium to large and are often strikingly coloured. The females construct multicellular nests in cavities, once built each cell is stocked with a spider, captured by the female. They are found in open habitats such as heaths, meadows and forest edges. There are 24 species of Cryptocheilus known from Europe, 6 from North America and 2 recently described from the Neotropics.