This review provides a brief introduction of the supramolecular biomaterials made of small molecules (especially peptides and peptide derivatives) because the ordered structures of molecular assemblies provide a versatile platform for designing emergent functions. We start with introducing common triggering mechanisms to initiate self-assembly. By discussing representative examples of supramolecular biomaterials formed intercellularly, peri/intracellularly, or subcellularly, we emphasize the applications of supramolecular biomaterials in the biomedicine, including tissue engineering, cancer therapy, drug delivery, and molecular imaging. Since a few comprehensive reviews of the related subjects already have been published (Du et al., 2015[17]; Zhou et al., 2017[124]), we mainly focus on representative examples in the past five years. Polymer supramolecular assemblies will not be included because of considerable disorders associated with conventional polymers.