Jaapiales is an order of fungi in the class Agaricomycetes (subclass Agaricomycetidae). It was first described in 2010 to contain Jaapia, a genus of resupinate species that were until then classified in the order Boletales. Molecular phylogenetics analysis showed it to be a sister group (one of two clades resulting from the splitting of a single lineage) to the rest of the Agaricomycetidae. The genus Jaapia, first described by Italian mycologist Giacomo Bresadola in 1911, contains two widely distributed species, J. argillacea and J. ochroleuca.