Matachia marplesi is a species of Desidae spider that is endemic to New Zealand.
This species was described by Ray Forster in 1970 from male and female specimens. The holotype is stored in Auckland War Memorial Museum.
The male is recorded at 7.65mm in length whereas the female is 8.67mm. The carapace is coloured reddish brown. The legs are yellow brown. The abdomen is patterned dorsally.
This species is only known from Great Island in Three Kings Islands, 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".