The Nectriaceae comprise a family of fungi in the order Hypocreales. It was circumscribed by brothers Charles and Louis René Tulasne in 1865. In 2020, an Outline of fungi was produced and listed 70 genera and about 1,336 species.

The Hypocreales are an order of fungi within the class Sordariomycetes. In 2008, it was estimated that it contained some 237 genera, and 2647 species in seven families. Since then, a considerable number of further taxa have been identified, including an additional family, the Stachybotryaceae. Wijayawardene et al. in 2020 added more families and genera to the order. According to the Catalog of Life, As of April 2021 the Hypocreales contains 6 families, 137 genera, and 1411 species. Hyde et al. (2020a) listed 14 families under Hypocreales, while, Wijayawardene et al. (2022) accepted 15 families in the order, where Cylindriaceae was additionally added. Earlier, Hyde et al. (2020a) had placed Cylindriaceae in class Xylariomycetidae. Samarakoon et al. (2022) agreed. Hence, Cylindriaceae should have been excluded from Hypocreales and placed in Xylariomycetidae. Xiao et al. (2022) recently introduced a new family Polycephalomycetaceae to Hypocreales.