The New Zealand pselaphine genus Stenosagola Broun (type species = S. planiocula Broun) comprises 21 species, 18 of which are described as new: Stenosagola pseudogracilis Park and Carlton, new species; Stenosagola clarkei Park and Carlton, new species; Stenosagola egmontensis Park and Carlton, new species; Stenosagola ramsayi Park and Carlton, new species; Stenosagola domettensis Park and Carlton, new species; Stenosagola eylesi Park and Carlton, new species; Stenosagola stewartensis Park and Carlton, new species; Stenosagola huiaensis Park and Carlton, new species; Stenosagola northlandensis Park and Carlton, new species; Stenosagola thayerae Park and Carlton, new species; Stenosagola dugdalei Park and Carlton, new species; Stenosagola tararuaensis Park and Carlton, new species; Stenosagola haunuiensis Park and Carlton, new species; Stenosagola pseudoconnata Park and Carlton, new species; Stenosagola chandleri Park and Carlton, new species; Stenosagola nunni Park and Carlton, new species; Stenosagola newtoni Park and Carlton, new species; Stenosagola butcheri Park and Carlton, new species; and Stenosagola fiordlandensis Park and Carlton, new species. Three species, Stenosagola crassicornis (Broun), Stenosagola oblongiceps Broun, and Stenosagola planiocula Broun, are synonymized under Stenosagola gracilis (Broun), and two species, Stenosagola griseipila Broun and Sagola longipennis Broun are synonymized under Stenosagola connata (Broun). A key to species, habitus photographs, and line drawings of diagnostic characters are provided.