Idiocnemis is a genus of damselflies in the family Platycnemididae. They are distributed on New Guinea and the surrounding islands. There are 20 species. The genus is divided into two groups. The Idiocnemis inornata group are mainly reddish brown in color with turquoise markings. The Idiocnemis bidentata group are brown to black with purple, blue, turquoise, or yellow markings. The groups can also be distinguished by the shape of the penis.