Dirofilaria immitis was found in 8 of 225 (3.6%) red foxes (Vulpes vulpes) collected from fur buyers and trappers in Bond, Clinton, DeKalb, Edgar, Ford, Jasper, Moultrie, and Richland counties, Illinois. Infections ranged from 1 to 23 nematodes per fox. The finding of D. immitis in red foxes represents a new host record for the state.