Campyloxenus is a bioluminescent genus of click beetles in the family Elateridae, and had been the sole member of the subfamily Campyloxeninae, until another monotypic genus Malalcahuello [species] was described from Chile in 2015 as its new member.

Antennae elongate, surpassing the hind angles of the prothorax, serrate from the fourth segment onwards; second segment short, third elongate, two times longer than second and of the same length as the fourth.

Luminous spots occupying the entire middle region on each side of the prothorax and visible beneath on the proepisternum.

Female genitalia: stylus and baculum elongate, eighth urosternite elongate inwardly; bursa copulatrix not spiraled, with a few sclerotized scales.

Sexual dimorphism accentuated; females with small eyes, more convex and more rounded prothorax; antennae shorter.