The occurrence of ectoparasite infestation in cattle contributes significantly to the success of cattle farming. A study on ectoparasite infestation in cattle (Bos sp.) was conducted in the oil palm plantation Afdeling II, Gunung Kataran Village, Tebing Tinggi Subdistrict, Serdang Bedagai Regency, North Sumatra. The research aimed to determine the types, prevalence, and intensity of infestation in three cattle breeds (Madrasin, Limousin, and Simmental), with each breed consisting of 10 individuals. Ectoparasite samples were collected using two methods: sweeping with a net and manual inspection of the entire cattle body. The identified ectoparasite species included Boophilus microplus, Musca domestica, Stomoxys calcitrans, Culex sp., and Haemadipsa sp. The prevalence of ectoparasite infestation across the three breeds (Madrasin, Limousin, and Simmental) ranged from 80% to 100%, falling into the ‘usually-always’ category. The intensity of ectoparasite infestation across the three breeds ranged from 4.22 to 97.4, categorized as ‘light-heavy’. Musca domestica emerged as the most dominant ectoparasite species affecting the cattle in this study. The presence of ectoparasites was found to be significantly influenced by the cleanliness of the rearing environment.”