Neumann's warbler was formally described in 1908 by the English zoologist Water Rothschild from specimens collected in a forested area west of Lake Tanganyika.

The specific epithet neumanni was chosen to honour the German ornithologist Oscar Neumann.

[8] Neumann's warbler is a small bird with an overall length of 10–11 cm (3.9–4.3 in) and a weight of 11.3 g (0.40 oz).

The broad supercilium is grey-brown and present in front of the eye as a dull greenish and white pattern.

[8] The voice is a loud song ("tee-tiyoo-tee", "tee-tyer-tyii", "tyoowi-tyee", "tee-teeyoo-tyoowi" or "tay-tiyoo-tay") intermixing with almost inaudible lipsing notes, and is repeated at regular intervals.