Species concepts are morphologically revised and updated for members of the mycophagous genus Hirtodrosophila Duda that occur in America north of Mexico. Photomicrographs of external features, illustrations of male and female terminalia, and detailed descriptions are provided for 12 species. One species, H. cinerea (Patterson and Wheeler) is known only from the original description; its status is uncertain. Species exclusively from the southwestern United States are H. grisea (Patterson and Wheeler), H. longala (Patterson and Wheeler), and H. orbospiracula (Patterson and Wheeler). Hirtodrosophila alabamensis (Sturtevant) and H. duncani (Sturtevant) are widespread throughout the eastern half of North America; the latter species is morphologically disparate for Hirtodrosophila but provisionally retained in the genus. Hirtodrosophila chagrinensis (Stalker and Spencer) is very rare, known only from two female specimens from the northern United States. Hirtodrosophila ordinaria (Coquillett) is the most widespread species of the genus in North America, occurring throughout the northern half of the continent up to Alaska; H. shaitanensis (Sidorenko) from far eastern Russia may be a junior synonym. A preliminary scheme of relationships in the H. melanderi species group (including H. ordinaria) is presented. Two species from Florida (H. pictiventris [Duda], H. prognatha [Sturtevant]) and one from Florida plus other Gulf states (H. thoracis [Williston]) are widespread throughout the Caribbean, Central America, and portions of South America. Hirtodrosophila mendeli (Mourão et al.), from Brazil, may be a junior synonym of H. prognatha. Two new species are described from southern Florida: H. florida, n. sp., and H. jaenikei n. sp., the latter in the nigrohalterata species complex. A key to the North American species is provided.