The assassin bug genus Coilopus Elkins, 1969 is recorded for the first time from Colombia. Coilopus vellus Elkins, 1969 is a wasp mimic that was previously recorded from Costa Rica, French Guiana, and Brazil. The Colombian specimens fill the distributional gap between the known Central and South American records. In addition, based on collected wasps from the same place as Coilopus, Mischocyttarus sp. (Vespidae: Polistinae) is proposed as the hymenopteran model of this mimetic harpactorine.