Spagnius is a genus of spiders in the family Dictynidae.
Spagnius is distributed across North America, occurring in Canada, the United States, and Mexico, with one species endemic to Cuba.
The genus is named after entomologist Joseph C. Spagna (1973-2024).
Males resemble the genus Eriena. The species included in this genus were previously part of the wastebasket taxon Dictyna.
, this genus includes four species: