Clinidium dux is a species of ground beetle in the subfamily Rhysodinae.[1] It was described by Ross Bell & J.R. Bell in 2009.[1] It is only known from the holotype, a female, collected from the island of Marinduque, the Philippines. The taxonomic affinities of this species remain uncertain as male specimens are unknown. The specific name refers to the type locality, duque (="duke") being derived from the Latin dux, meaning "leader".
Clinidium dux holotype measures 7.52NaN2 in length.