The order Ceratobasidiales is a group of fungi within the class Agaricomycetes known primarily for their role as plant pathogens, mycorrhizal partners, or saprotrophs. Members of this order typically produce basidiocarps that are thin, effused, and corticioid (resupinate), with a smooth to slightly warted surface. They often have a simple hyphal system with clamp connections and produce basidiospores that are typically smooth and thin-walled. Many Ceratobasidiales species are associated with root diseases in plants, while some form beneficial mycorrhizal associations with orchids. Ecologically, they are widespread and play important roles in nutrient cycling, plant health, and ecosystem dynamics.