In 2003, three specimens of Koreanosaurus were found in the Late Cretaceous-age Seonso Conglomerate from the southern coast of the Bibong-ri dinosaur egg site, Boseong, Korean Peninsula.

[3] Koreanosaurus was a relatively small dinosaur, reaching 2–2.4 meters (6.6–7.9 ft) in body length.

[7] Koreanosaurus was considered to be a basal member of the Ornithopoda by the authors, forming a clade with Zephyrosaurus schaffi, Orodromeus makelai and Oryctodromeus cubicularis from which they deduced a burrowing lifestyle.

[3] In 2012, Han et al. found it plausible that Koreanosaurus might be a member of Jeholosauridae or closely related to it.

[8] Subsequent phylogenetic analyses by researchers including Han et al. consistently classified Koreanosaurus as a member of Thescelosauridae,[9] specifically within the subfamily Orodrominae.