Osteina is a fungal genus in the family Dacryobolaceae.

The genus was circumscribed by mycologist Marinus Anton Donk in 1966, with Polyporus obductus as the type species.

[1] Catalogue of Life lists 3 accepted species:[2] Osteina is characterized by fruit bodies that are sessile to stipitate, which are bone hard when dry.

It has a monomitic hyphal system, containing only generative hyphae with clamps.

The spores are hyaline and thin-walled, and are inamyloid and acyanophilic.