The Miaogou Formation is a geological formation in Inner Mongolia, north China. While its absolute age is uncertain, it has been estimated to represent Early Cretaceous sediments based on the faunal composition. Dinosaur remains are among the fossils that have been recovered from the formation.

The primary fossil-producing outcrop of the Miaogou Formation is the Maortu locality, which was discovered in 1959 by a joint expedition of Chinese and Russian paleontologists. Initial reports of the locality's fauna incorrectly assigned the fossils to either the Ulansuhai or Dashuigou formations, but a later discussion corrected this.

While the Miaogou Formation has not been absolutely dated, estimates based on charophytan, stratigraphic, and sedimentological studies have proposed a Barremian–Albian age range. However, a more narrow range (around Aptian-Albian) is implied based on the fossil animals found in the formation, which are inconsistent with Chinese Barremian faunas such as those associated with the Jehol Biota.

Analysis of the formation's geology indicates that it represents a hot, humid environment with large lake systems. The formation's lower member preserves alluvial fan to braided stream deposits, while the upper member preserves meandering stream and lacustrine deposits.