The Grey-crowned Flatbill is widespread in Amazonia, with records up to 1,300 m along the Andean foothills. It may forage in mixed-species flocks in the canopy of river-edge forest and on river islands.
The upperparts are yellow-olive, and the wing feathers have yellow edges. The breast is dull yellow and grades to deeper yellow on the belly; the crown is gray. The bill is mostly black with a pale base to the lower mandible.
It forages in the canopy and subcanopy at varzea forest edges, on river islands, and in tall second growth. It is sometimes with mixed-species flocks.
An extinction-risk assessment has not been added yet.