Idiops nigropilosus is a species of spider in the family Idiopidae. It is endemic to South Africa.
Idiops nigropilosus is recorded from Gauteng and Mpumalanga. The species occurs at an altitude of 1,698 m above sea level.
The species inhabits the Grassland biome. It lives in silk-lined burrows closed with a trapdoor.
Idiops nigropilosus is known from both sexes and has been partly illustrated.
Idiops nigropilosus is listed as Data Deficient due to insufficient knowledge about its location, distribution and threats. The species is under-collected and identification is still problematic. More sampling is needed to determine the species' range.
The species was originally described by John Hewitt in 1919 as Acanthodon nigropilosus from Carolina. The species has not been revised.