Four species of Lyomyces (Hymenochaetales, Basidiomycota) are described as new for science, based on collections from Réunion Island (L. allantosporus and L. mascarensis), southeast Brazil (L.organensis), and Taiwan (L. orientalis). All four species belong to the L. sambuci complex and grow on dead wood. Basidiomata photographs and line drawings of microstructures are provided for each species. The specific status of the new taxa was confirmed by ITS and 28S phylogenetical analyses. The concept of L. sambuci s. str. is discussed. Molecular data reveal one additional cryptic species from Europe, morphologically identical with L. sambuci s. str.