Sarcoscypha dudleyi, commonly known as the crimson cup or the scarlet cup, is a species of fungus in the family Sarcoscyphaceae of the order Pezizales. In addition to its main distribution in the central to eastern United States, the fungus has also been recorded once in Bulgaria. It has been frequently confused with Sarcoscypha coccinea, but can be distinguished from this and other related species in Sarcoscypha by differences in microscopic characteristics, such as the presence and number of oil droplets in the spores. The species Molliardiomyces dudleyi is an imperfect form of the fungus that lacks a sexually reproductive stage in its life cycle.