Hemoproteins are metalloproteins which include iron porphyrin as a cofactor. These proteins have received much attention as promising building blocks for development of new types of biomaterials. This review summarizes recent efforts in the rational design of supramolecular hemoprotein assemblies using myoglobin, horseradish peroxidase, cytochrome b562 and cytochrome c as a monomer unit. The processes of coordination bond-mediated assembly or domain swapping-mediated assembly provide defined oligomers, while hemoprotein reconstitution with synthetic heme derivatives provides submicrometer-sized structures such as fibrils, vesicles/micelles, or networks. Interestingly, several of these assembled structures maintain the intrinsic functions of monomer units. The chemical and/or biological strategies described in this review will lead to the creation of unique hemoprotein-based functional biomaterials.