A new brachypterous species of Onthophagus from Mexico, belonging to the New World chevrolati species group, is described and illustrated. Illustrations of the male and female dorsal habitus, and genitalia are provided. The relationships with other brachypterous species that occur in Guerrero (Mexico) are discussed. Placement of the new species in the chevrolati group key is provided. Additionally, new locality records for O. inflaticollis Bates are provided.http://www.zoobank.org/urn:lsid:zoobank.org:pub:747118CE-6A93-401A-8625-5A75479980AD