Oligogonotylus mayae n. sp. is described from the intestine of the Mayan cichlid Cichlasoma urophthalmus (Günther) in Ría Lagartos, Ría Celestún, and Estero Progreso, Yucatán State. This is the second species described for OligogonotylusWatson, 1976, the other being O. manteriWatson, 1976. The new species is readily distinguished from O. manteri by the anterior extension of the vitelline follicles. In O. manteri, vitelline follicles are found entirely in the hindbody, extending posteriorly to mid-testicular level. Vitelline follicles in the new species extend from the anterior margin of posterior testis to the region between the ventral sucker and the pharynx. Comparison of approximately 1,850 bases of ribosomal DNA (ITS1, ITS2, 5.8S, and 28S), and 400 bases of cytochrome c oxidase subunit I (cox1) strongly supports the status of O. mayae as a new species, as compared to O. manteri collected from cichlids in other localities of Mexico, Belize, and Guatemala.