West Nile virus (WNV) is a virus that is commonly found in avian species in the Midwestern United States. WNV commonly follows a bird-mosquito-bird transmission pattern, with birds serving as amplifying hosts, or reservoirs, for the pathogen. We analyzed plasma samples from raptor species that were admitted to a rehabilitation clinic in Central Illinois for two types of antibodies against WNV using an enzyme-linked immunosorbent assay (ELISA). In all, eight different raptor species were tested. From our survey, we found that Great-Horned Owls (Bubo virginianus) had the highest seroprevalence (38.6%) and Turkey Vultures (Cathartes aura) had the lowest seroprevalence (11.1%) for IgY antibodies. The highest seroprevalence for IgM antibodies was for American Kestrels (Falco sparvarius) with 28.2% and the lowest was Great-Horned Owls with 0.2%. We also saw patterns of increased WNV-positive birds of prey sampled in seasons when mosquitoes are most active in Central Illinois.