Scaffold web spiders or cave cobweb spiders (Nesticidae) are a family of araneomorph spiders closely allied with tangle-web spiders (Theridiidae). Like the Theridiidae, these spiders have a comb of serrated bristles on the hind tarsi that are used to pull silk bands from the spinnerets. Nesticidae contains 16 genera and about 300 species, many of which are associated with caves or overhangs.

The genus Nesticus is the type for the family and is found throughout the world. The related Eidmannella has speciated considerably in Texas caves and includes some extremely localized species that are considered threatened. One species, Eidmannella pallida, is found in caves and under overhangs, but also in agricultural fields and other habitats away from such restricted areas. The genus Carpathonesticus is found in central Eurasia.

As of October 2025^[update], this family includes sixteen genera:

The following extinct genera have been placed in the Nesticidae: