Onthophagus nuchicornis is a species of dung beetle in the family Scarabaeidae. It is found in Europe and North America. Though Onthophagus nuchicornis is listed as "Vulnerable" in the United Kingdom, it is a common and abundant species in North America. It has been used as a model organism for ecotoxicological studies of ivermectin, where different biological endpoints are stimulated at low levels of ivermectin exposure, but impaired at high levels of ivermectin exposure.