Collagen, the most abundant protein in mammals, not only provides tensile strength to tissues and organs, but also interacts with a myriad of proteins, namely collagen-binding proteins (CBPs), to regulate cell adhesion, growth, and differentiation. Despite their significant biological importance, the interactions between collagen and CBPs are poorly understood because of its insoluble, large, and anisotropic natures of collagen. In this review, I describe the recent progress in understanding the collagen-CBP interactions, which is primarily accelerated by the use of homo- and heterotrimeric collagen-like model peptides coupled with a variety of physicochemical and structural biological techniques. The detailed analyses on the collagen-CBP interactions are important for understanding the biological functions of collagen and its related diseases, and potentially provide a clue to develop novel collagen mimetic materials.