The grey-crowned flatbill or grey-crowned flycatcher (Tolmomyias poliocephalus) is a species of bird in the family Tyrannidae.It is found in humid forest in the Amazon and Atlantic Forest in South America. It closely resembles the yellow-margined and yellow-olive flatbills, but its lower mandible is dark with a pale base. It is a fairly common bird with a wide range and the International Union for Conservation of Nature has rated it as "least concern".