The Bougainville Fantail occurs on Bougainville Island. Adults of the nominate form have a gray crown, a white forehead and eyebrow, and buff-washed body plumage. A 2024 survey recorded it in mountain moss forest.
Adults of the Bougainville nominate form have a dark mouse-gray crown and a white forehead stripe continuing above the eye. The back, wings, tail, breast, and belly show an ochre-buff wash.
In a 2024 survey, the species was common in moss forest on Mt Balbi between about 1,580 and 2,120 m and was not recorded in elfin forest. There was one record at about 1,250 m at Keriaka.
An extinction-risk assessment has not been added yet.