Molecular analyses of soil and water commonly reveal large proportions of fungal taxa that cannot be assigned to any taxonomic or functional groups. Some of these so-called dark taxa have been encoded alphanumerically, while others have remained completely overlooked. Using long-read sequencing that covers much of the ribosomal RNA operon, we shed light on the phylogenetic and ecological distribution of fungal dark taxa and formally describe 30 of the most prominent phylum- to order-level lineages based on their characteristic DNA features. This increases the known large-scale fungal phylogenetic diversity by roughly one-third. Formal names will enhance taxonomic reproducibility, facilitate communication among researchers, and enable the estimation of conservation and quarantine needs for uncultivable species and higher-ranking taxa. The new species in the respective highest-level novel taxonomic groups include Pantelleria saittana (Pantelleriomycetes), Paraspizellomyces parrentiae (Paraspizellomycetales), Aquieurochytrium lacustre (Aquieurochytriomycetes), Edaphochytrium valuojaense (Edaphochytriomycetes), Tibetochytrium taylorii (Tibetochytriomycetes), Tropicochytrium toronegroense (Tropicochytriomycetes), Algovorax scenedesmi (comb. nov.) and Solivorax pantropicus (Algovoracomycetes), Aquamastix sanduskyensis (Aquamastigomycetes), Cantoromastix holarctica (Cantoromastigomycetes), Dobrisimastix vlkii (Dobrisimastigomycetes), Palomastix lacustris (Palomastigomycetes), Sedimentomastix tueriensis (Sedimentomastigomycetes), Terrincola waldropii (Terrincolales), Curlevskia holarctica (Curlevskiomycota), Mycosocceria estonica (Mycosocceriales), Maerjamyces jumpponenii (Maerjamycetes), Ruderalia cosmopolita (Ruderaliomycetes), Bryolpidium mundanum (Bryolpidiomycetes), Chthonolpidium enigmatum (Chthonolpidiomycetes), Savannolpidium raadiense (Savannolpidiomycetes), Gelotisporidium boreale (Gelotisporidiomycetes), Sumavosporidium sylvestre (Sumavosporidiomycetes), Parakickxella borikenica (Parakickxellomycetes), Aldinomyces tarquinii (Aldinomycota), Borikenia urbinae (Borikeniomycota), Mirabilomyces abrukanus (Mirabilomycota), Nematovomyces vermicola (comb. nov.) and N. soinasteënsis (Nematovomycota), Viljandia globalis (Viljandiomycota), Waitukubulimyces cliftonii (Waitukubulimycota), and Tartumyces setoi (Tartumyceta).