Cyonosaurus is a genus of gorgonopsian therapsids from the late Permian of South Africa. Some skulls have been reported from Early Triassic strata, but further investigation revealed that these reports were erroneous. Cyonosaurus was 0.6 to 1.1 m in length, with a skull 9 to 18 cm in length. The type species Cyonosaurus longiceps was named in 1937.