Metafroneta sinuosa is a species of sheet weaver spider endemic to New Zealand.
This species was described in 2002 by A.D Blest and Cor Vink from male and female specimens. The holotype is stored in Otago Museum.
The male is recorded at 3.42mm in length whereas the female is 4.42mm. This species has a brown cephalothorax and yellow brown legs.
This species is only known from Dunedin and Fiordland in New Zealand.
Under the New Zealand Threat Classification System, this species is listed as "Naturally Uncommon" with the qualifier of "Range Restricted".