Adult, free-ranging cougars (Puma concolor) were sampled in three regions of Utah, US, from 2018 to 2021. A total of 68% (23/34) of the sampled cougars had antibodies to feline parvovirus, 15% (5/33) to canine distemper virus, 18% (6/34) to calicivirus, and 22% (8/37) to Yersinia pestis. Forty-one percent (13/32) had IgG antibodies to Toxoplasma gondii and 6% (2/33) to feline immunodeficiency virus, and 3% (1/32) were positive for Dirofilaria immitis (heartworm) antigen. All were seronegative for Toxoplasma gondii IgM, feline enteric coronavirus, SARS-CoV-2, feline leukemia virus, feline herpesvirus, and Francisella tularensis. Tapeworms and Toxascaris leonina eggs were detected in the feces. The disease exposures detected were similar to what has been reported from cougar populations in other western US states, and the current level of exposures is unlikely to have a negative impact on the state's population.