The sooty thicket fantail (Rhipidura threnothorax) is a species of bird in the family Rhipiduridae. It is found in New Guinea.
The majority of fantails are strong fliers, and some species can undertake long migrations, but sooty thicket fantail as well as the other thicket fantails (white-bellied thicket fantail and black thicket fantail) are very weak fliers, and need to alight regularly.
Its natural habitat is subtropical or tropical moist lowland forests.