Self-assembled peptide materials have emerged as promising bioinspired tools for applications that include regenerative medicine, drug delivery, antimicrobial and vaccine development, optics, and catalysis. Peptide self-assembly mediated by noncovalent hydrogen bonding, coulombic, hydrophobic, and aromatic interactions gives rise to a variety of supramolecular structures that reflect on the nature of the constituent peptides. The emergent properties of these supramolecular peptide materials often depend on the multivalent presentation of functional appendages on the self-assembled scaffold. For example, the multivalent display of cell-signaling motifs on self-assembled peptide nanofibrils provides materials that are excellent extracellular matrix mimetics for tissue engineering applications. This review includes a discussion of chemical strategies that address the challenge of appending functional signal motifs in a multivalent display on self-assembled peptide and protein materials. In addition, recent examples of supramolecular peptide materials that rely on the multivalent display of chemical signals for the desired applications are presented. Collectively, this discussion illustrates the potential of self-assembled peptides as sustainable materials to address challenges in contemporary materials science and provides principles for the design of next-generation agents for a variety of applications.