Roberts's warbler was first formally described as Prinia robertsi in 1946 by the British ornithologist Constantine Walter Benson, although it had originally been identified as a distinct species at Mount Selinda by Charles Swynnerton in 1906.

[6] Roberts's warbler has the genus name Oreophiilias which Clancey explained as combining oreophil, being Greek meaning "mountain-loving", with lais, which is derived from hypolais, a small warbler-like songbird.

[4] The specific name honours the South African ornithologist Austin Roberts in recognition of his contribution to the ornithology of southern Africa.

[4] It is a dark-grey warbler which bears the closest resemblance to is the tawny-flanked prinia (P. subflava) but differs in having a grey throat, pale eye and lake of brown edges to feathers of the upperparts.

[8] Robert's warbler is endemic to the Eastern Highlands of Zimbabwe where it is found from the Chimanimani Mountains in the south to Nyanga in the north, typically at altitudes above 1,200 m (3,900 ft), where it appears to replace the tawny-flanked prinia, although the two species overlap with Roberts's warbler preferring denser cover than the prinia.

The nest is oval in shape with an entrance offset at the top and it is made from fine grasses and moss, held together with spider web and located about 1 m (3 ft 3 in) above the ground.