Thelypteris soridepressa, known only from the type collection, is described and illustrated. The species belongs to subg. Amauropelta sect. Apelta A.R. Sm. It is superficially similar to Thelypteris micula from Peru in its small, very thin-textured leaves and short trichomes on the adaxial surface of the veins, but can be distinguished by the lack of resinous dots and indusia, as well as by its sunken sori. It has no close relatives in Brazil.