Sebastes ventricosus, the Japanese black seaperch or Japanese blueback seaperch, is a species of marine ray-finned fish belonging to the subfamily Sebastinae, the rockfishes, part of the family Scorpaenidae.

Sebastes ventricosus was first formally described in 1843 by the zoologists Coenraad Jacob Temminck and Hermann Schlegel with the type locality given as Nagasaki.

The specific name ventricosus means "potbellied or bulging", an allusion which was not explained by the authors nor is it evident what it refers to, it may be alluding to the rounded nape or possibly the ventral profile which is shown as bulging in the plate accompanying the description.

[2] Sebastes ventricosus has been recorded from Iwate and Ishikawa Prefectures south to Kyushu in Japan, and off the southern part of the Korean Peninsula.

[4] Sea perch are very popular seawater game fish highly prized especially by fishermen, because they generally put up a good fight when caught with a hook and line.