The Korean sandlance (Hypoptychus dybowskii) is a species of marine ray-finned fish belonging to the family Hypoptychidae.

The Korean sandlance was first formally described in 1880 by the Austrian ichthyologist Franz Steindachner with its type locality given as Peter the Great Bay.

[4] Other authorities treat the Gasterosteoidei as the infraorder Gasterosteales within the suborder Cottoidei or as a sister clade to the Zoarcales in the order Zoarciformes.

[5] Some authorities include the tubenose (Aulichthys japonicus) in the Hypoptychidae,[3][6] but the 5th edition of Fishes of the World puts this taxon in the family Aulorhynchidae.

[9] The Korean sandlance is found in the northwestern Pacific Ocean where it occurs in the coastal waters off of northern Honshu and Hokkaido in Japan, Sakhalin, and the Kuril Islands.

Study of the otoliths has shown that this species lives up to a year old,[1] Like sticklebacks, it feeds on small invertebrates and fish larvae.