Eurotiales is an order of fungi within the class Eurotiomycetes of the phylum Ascomycota. Members of this order are typically saprophytic, living on decaying organic matter, although some are pathogenic to plants, animals, or humans. They are characterized by producing asexual spores (conidia) in specialized structures called conidiophores and sexual spores (ascospores) within cleistothecia, which are closed fruiting bodies. Eurotiales includes economically and medically important genera such as Aspergillus and Penicillium, known for their roles in fermentation, antibiotic production, food spoilage, and opportunistic infections. These fungi are widely distributed in soil, air, and indoor environments, thriving in diverse ecological niches.