Reinga waipoua is a species of spider in the family Desidae that is endemic to New Zealand.
This species was described by Ray Forster and Cecil Wilton in 1973 from female and male specimens. The holotype is stored in Otago Museum.
The female is recorded at 3mm in length whereas the male is 4.4mm. The carapace is coloured pale cream. The legs are pale. The abdomen has a pale cross marking dorsally.
This species is only known from Northland, New Zealand.
Under the New Zealand Threat Classification System, this species is listed as "Data Deficient" with the qualifiers of "Data Poor: Size" and "Data Poor: Trend".