Parasitiformes are a superorder of Arachnids, constituting one of the two major groups of mites, alongside Acariformes.

For example, about half of the 10,000 known species in the suborder Mesostigmata are predatory and cryptozoan, living in soil-litter, rotting wood, dung, carrion, nests or house dust.

A few species have switched to grazing on fungi or ingesting spores or pollen.

The oldest known fossils of Parasitiformes, representing three out of the four modern groups, Ixodida, Mesostigmata, and Opilioacarida, are known from Cretaceous aged amber, dating to around 100 million years ago.

The genetic divergence between the groups is less than that of Acariform mites, suggesting a younger origin, likely dating to the late Paleozoic.