Few studies have characterized the prevalence of intraerythrocytic parasites in free-ranging chelonian populations or their occurrence across habitats. It is hypothesized that chelonians in different habitats have different exposures to vectors and thus differences in hemoparasite presence. This study explored the prevalence and intensity of intraerythrocytic parasites by examining blood smears from four species of Illinois turtles: wild Blanding's turtle (Emydoidea blandingii), eastern box turtle (Terrapene carolina carolina), ornate box turtle (Terrapene ornata ornata), and prerelease head-started alligator snapping turtle (Macrochelys temminckii). Intraerythrocytic parasites were identified in all examined species except for the alligator snapping turtle. For all age classes, Blanding's turtles had both the highest prevalence of hemoparasites and the highest intensity of infection of all sampled species, whereas adult Blanding's turtles had a significantly higher prevalence than juveniles (P < 0.05). Because this is the first study of hemoparasites in Illinois chelonians, further research is needed to identify the specific species of intraerythrocytic parasite, the potential vectors, and the effect that these hemoparasites have on the health of chelonians.