This supplement to the taxonomic monograph The Genera of Hyphomycetes summarises information on 23 accepted new genera and c. 160 species described in 2011. These include three dematiaceous genera (Funbolia, Noosia, Pyrigemmula, all related to Dothideomycetes), a bulbil-producing genus, Spiroplana (Pleosporales), and two endophytic genera, the sterile Periglandula (Clavicipitaceae), and the hyaline, sympodial Micronematobotrys (Pyronemataceae). Slow-growing, morphologically-reduced, darkly pigmented fungi continue to be the source of new taxa, including the new genus Atramixtia (Dothioraceae). Eight new genera of darkly pigmented chlamydosporelike anamorphs were described from marine or subtidal environments (Glomerulispora, Halozoön, Hiogispora, Matsusporium, Moheitospora, Moleospora, Moromyces), mostly associated with subclades of the Lulworthiales. Several genera that are morphologically similar to but phylogenetically distinct from genera of the Capnodiales (Pseudopassalora, Scleroramularia) were introduced, as well as segregates from the classical concepts of Alternaria (Sinomyces), Chalara and Phialophora (Brachyalara, Infundichalara, Lasiadelphia), and Paecilomyces (Purpureocillium for the former Paecilomyces lilacinus complex). In addition, in anticipation of the new nomenclatural rules, newly configured formerly-teleomorph genera were proposed as segregates from classical hyphomycete genera in the Hypocreales, namely Acremonium (Cosmospora), Fusarium (Cyanonectria, Dialonectria, Geejayessia, Macroconia, Stylonectria), and Volutella (Pseudonectria) and the Trichocomaceae, Eurotiales, Penicillium (Talaromyces for the former Penicillium subg. Biverticillium). Standardized generic mini-diagnoses are provided for the accepted new genera, along with details of distribution, substrates, numbers of new species and phylogenetic affinities within the Dikarya. GenBank accession numbers for ITS DNA-barcodes are provided where available. New information on generic concepts of previously recognised genera, phylogenetic relationships, and corrections of factual errors are also included. Only two newly described genera, Fecundostilbum and Utrechtiana, seem to be synonyms of previously described genera.