The Hasandong Formation (Korean: 하산동층; Hanja: 霞山洞層; RR: Hasandong-cheung) is an Early Cretaceous (Aptian to Albian) geologic formation in South Korea. It has been dated to the late Aptian and earliest Albian, between 118.0 ± 2.6 Ma and 112.4 ± 1.3 Ma. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation. Tracks of the pterosaur ichnospecies Pteraichnus koreanensis have also been recovered from the unit.