The Blackish Antbird is widely distributed in South America east of the Andes, in the foothills from southern Colombia south to Peru, and across Amazonia from Colombia south to Bolivia and east to central Brazil. In Amazonia, this species primarily occurs south of the Amazon River, but the nominate subspecies is distributed locally from the north bank of the Amazon to the Guianas. Six subspecies of Blackish Antbird are recognized. The males of all populations are some shade of very dark gray, with tiny white markings on the wings, whilst females are principally cinnamon below, becoming rather duller and browner above. Like other Cercomacra, this species is an inhabitant of dense undergrowth in a wide variety of forest types below 2200 m.