Mythicomyiidae, commonly called mythicomyiids, are very tiny flies (0.5–5.0 mm) found throughout most parts of the world, especially desert and semi-desert regions, except the highest altitudes and latitudes.

Many of these "microbombyliids" have a humpbacked thorax (as in the Acroceridae) and lack the dense vestiture common in the Bombyliidae.

A high diversity of both genera and species exists for this family in Africa, especially northern and southern portions.

Because of their extremely small size and curious body shapes, some genera have been at times placed in the Acroceridae or Empididae.

Augmenting the morphological characters, it is also a much older lineage than any known Bombyliidae, dating from as far back as the Middle Jurassic (Palaeoplatypygus Kovalev; Callovian: 163–168 mya) with other genera known from the Cretaceous (Procyrtosia Hennig and Proplatypygus Zaitzev).