Capnodiales is a diverse order of Dothideomycetes, initially based on the family Capnodiaceae, also known as sooty mold fungi. Sooty molds grow as epiphytes, forming masses of black cells on plant leaves and are often associated with the honeydew secreted by insects feeding on plant sap. This diverse order has been expanded by the addition of several families formerly thought unrelated and now also includes saprobes, endophytes, plant pathogens, lichens and rock-inhabiting fungi. The new additions include the genus Mycosphaerella containing the causal agents of several economically important crop and tree diseases. A small number of these fungi are also able to parasitise humans and animals, including species able to colonise human hair shafts.

Dothideomycetes is the largest and most diverse class of ascomycete fungi. It comprises 11 orders 90 families, 1,300 genera and over 19,000 known species. Wijayawardene et al. in 2020 added more orders to the class.