BackgroundGrowing vaccination hesitancy is well-document among humans. However, we know very little about vaccination hesitancy for pets as well as whether the two phenomena are interconnected. Moreover, support for pet vaccination requirements also remain underassessed. MethodsWe fielded a large, national survey (N = 3,958) on August 18 and August 19, 2023, to assess U.S. public opinion about the vaccination status of dogs (rabies, canine parvovirus, canine distemper, canine influenza, and Lyme disease) and cats (rabies, feline panleukopenia (parvo), feline herpesvirus-1, feline chlamydia, and feline Bordetella) in the United States. We also queried respondents about their support for vaccination requirements for the 10 diseases. ResultsWe find that the vast majority of cats and dogs are vaccinated. However, a substantial minority of pets is not, particularly for cats and for non-core vaccines. We find that attitudinal measures of human and pet vaccine hesitancy are closely related to each other. Moreover, they are strong predictors of vaccine behavior. Measures of vaccine hesitancy are also strong predictors of support for vaccination mandates. Common measures used to assess human vaccine hesitancy showed inconsistent effects. However, pet vaccinations appear to be less politically polarizing. ConclusionThe high correlation between pet and human measures raises the stake for public health efforts to improve attitudes about vaccines and vaccination rates across the board. Strong support for vaccination requirements should encourage policymakers to explore policy change. Moreover, veterinarians and their associations should consider expanding the number of core vaccinations.