A taxonomic treatment of Bromus in México and Central America is presented. Twenty-two species and one variety are recognized in the region. Twelve of these species are native, and ten are adventive and introduced. Bromus section Mexibromus is newly described, representing a distinct lineage in molecular studies of the genus. It includes two species endemic to México (B. attenuatus, B. densus) and one endemic to México and Guatemala (B. dolichocarpus), distinguished from species in other Bromus sections by their 3(–5)-nerved lemmas. Bromus pinetorum is a poorly understood species of Bromus sect. Bromopsis endemic to Coahuila. Taxa that have been variously treated in the past are discussed in detail. Bromus mucroglumis and B. thysanoglottis are treated as synonyms of B. richardsonii, and B. meyeri is treated as a synonym of B. anomalus. Two varieties are recognized in B. carinatus, B. carinatus var. carinatus and B. carinatus var. marginatus. Lectotypes are designated for the names B. carinatus var. californicus, B. hookeri var. schlechtendalii, B. trinii, B. trinii var. pallidiflorus and B. trinii var. stricta. A second-step neotype is designated for B. rigidus. Keys for determining the species in English and Spanish, descriptions, synonymies, illustrations, distribution maps, comments and lists of all specimens examined are provided for each species.