Bajaichthys is an extinct genus of Eocene zeid. It includes one species, Bajaichthys elegans. It is sometimes mistaken for a lampriform.
The holotype is four centimeters in length. It has a deep, oblong-shaped body, a deep, but short head, a long tail composed of 27 caudal vertebrae, a long, crest-like dorsal fin, a long, banner-like anal fin with 29 to 30 rays running from the posterior region of the body down the entire length of the tail, and two enormous, wing-like pelvic fins.