The golden-winged warbler is a threatened species in Canada, and the impact of blood parasites to the conservation of this species is poorly understood. I investigated whether landscape cover of agriculture, local human disturbance, historical dispersal of golden-winged warblers, and hybridization with a closely related species affected the prevalence of parasites in this species. Golden-winged warbler populations that had more recently colonized an area, and had higher landscape cover of agriculture, were more likely to be infected with Leucocytozoon and Haemoproteus parasites. Golden-winged warblers with local home ranges containing more rangeland were more likely to be infected with Haemoproteus, and hybrid golden-winged x blue-winged warblers were more likely to be infected with Leucocytozoon than pure golden-winged warblers. Because blood parasite communities in golden-winged warblers are shaped by factors that are important to conservation, their role is worth further exploration for this and other species.