Amphinecta dejecta is a species of Desidae that is endemic to New Zealand.
This species was described by Ray Forster and Cecil Wilton in 1973 from male specimens. The holotype is stored in Otago Museum.
The male is recorded at 13.5mm in length.
This species is only known from Fiordland, New Zealand.
Under the New Zealand Threat Classification System, this species is listed as "Naturally Uncommon" with the qualifiers of "Data Poor: Size" and "Data Poor: Trend".