Powellisetia bilirata is a species of marine gastropod mollusc in the family Rissoidae.

[1] First described by Winston Ponder in 1965, it is endemic to the waters of New Zealand.

Powellisetia bilirata has a minute shell, with four whorls angled by a strongle spiral chord.

The species is pale yellow-brown in colour, with a reddish-brown protoconch.

[1] The holotype was collected by K. Hipkins on 9 April 1955 from shell sand at McGregors Bay, Whangārei Heads, Northland Region.