Cynodonichthys is a genus of freshwater killifish in the family Rivulidae. They are found in Middle America, ranging from southern Mexico (north to Oaxaca and the Yucatán Peninsula), through Central America (where most species live), to Colombia (in the northwest and the Magdalena River basin). They are non-annual killifish (similar to relatives such as Anablepsoides, Atlantirivulus, Laimosemion and Melanorivulus) and inhabit small forest streams from the lowlands to an altitude of 1,500 m (4,900 ft).