The members of the subfamily Triatominae (Heteroptera, Reduviidae) are vectors of Trypanosoma cruzi (Chagas), the causative agent of Chagas disease or American trypanosomiasis. As important vectors, triatomine bugs have attracted ongoing attention, and thus, various aspects of their systematics, biology, ecology, biogeography, and evolution have been studied for decades. In the present chapter, the authors summarize the current knowledge on the systematics, phylogeny, evolution, and biology of these vectors and discuss the implications for human health.