Hyphodermella brunneocontexta sp. nov. (Basidiomycota, Hymenochaetales), collected in Mayotte (France, Comoros archipelago, Indian Ocean), is described and illustrated. The new species is characterized by a resupinate basidiome with many, very small aculei, locally with odontioid appearance, with apically projecting, heavily encrusted single to three or four congregated hyphae, a monomitic hyphal system with simple septate hyphae, clavate or subcylindrical, sometimes stocky basidia, and ellipsoid, oboval to subglobose, smooth, thin-walled, non-amyloid spores. The most important feature is the brown context with thick-walled hyphae, densely interwoven, welded together, sometimes forming a pseudoparenchymatic texture, particularly in the subiculum, which, in addition, is crammed with crystal conglomerates.