Trichoderma koningii is among the most commonly cited species in the genus. The morphological species Trichoderma koningii can be considered to be stereotypical of Trichoderma, viz. conidiophore with a more or less conspicuous main axis from which often paired lateral branches arise, the branches increasing in length with distance from the tip of the main axis and themselves branching in the same manner. As is the case with most Trichoderma species, conidia are ellipsoidal to oblong, smooth, and green. Teleomorphs of fungi having the ‘koningii’ morphology are very similar to the teleomorph of T. viride (Hypocrea rufa) and are not diagnostic, or are marginally diagnostic, of species. Ascospores are hyaline; stromata are at first semieffused, tan and villose but may become tuberculate, pulvinate to discoidal and brown to red-brown, ostiolar openings are typically not visible or at most barely visible on the stroma surface.  Phylogenetic analysis utilizing partial sequences of the translation-elongation factor 1 alpha (tef1), as well as fragments of actin and calmodulin genes, indicate that morphological characters typical of T. koningii evolved independently in three well-separated main lineages with no fewer than fourteen phylogenetic species. Multivariate analysis of phenotype characters combined with patterns of geographic distribution of members of clades supported the phylogenetic analysis. Combined molecular and phenotype data lead to the development of a taxonomy with the recognition of twelve taxonomic species and one variety. The few phenotype characters that were useful in species recognition include growth rate, colony characters and conidium size and morphology. Despite many reports of its widespread distribution, T. koningii s. str. was found to be an uncommon species restricted to Europe and eastern North America; itis redescribed. Trichoderma caribbaeum var. aequatoriale, T. koningiopsis, and T. ovalisporum were isolated as endophytes of trunks of Theobroma species in tropical America, and T. ovalisporum was isolated also as an endophyte from the woody liana Banisteropsis caapi that was infected with Crinipellis perniciosa in Ecuador. Trichoderma koningiopsis was found to be common in tropical America but was isolated also from natural substrata in East Africa, Europe and Canada, and from ascospores in eastern North America. Several additional new species, which are known only, or almost exclusively, from their teleomorphs, are T. austrokoningii, T. dingleyae, T. dorotheae, from Australia and New Zealand; T. petersenii, T. rogersonii from eastern North America and western Europe; T. intricatum is known from two teleomorph collections respectively from the Caribbean region and Thailand and T. taiwanense is known from a single teleomorph collection made in Taiwan. Isolates of T. ovalisporum and T. koningiopsis may have biological control potential. A classical morphophenetic key and a set of tools for molecular species identification were developed.