Supramolecular self-assembly represents a spontaneous and reversible process that bridges discrete molecular building blocks with nanoscale architecture through non-covalent interactions. By rationally tuning these interactions, diverse nanostructures can be precisely constructed, each exhibiting distinct physicochemical and functional properties. The dynamic and multivalent nature of supramolecular assemblies endows them with structural adaptability and cooperative binding, enabling responsiveness to environmental cues and amplification of weak molecular interactions. Nature provides abundant paradigms for such self-organization, in which organized supramolecular interfaces mediate complex biological functions. Inspired by these natural principles, artificial self-assembly systems have been engineered to emulate the hierarchical organization and functional adaptability of living systems. In this Review, we summarize recent advances in nature-inspired supramolecular assemblies, focusing on peptide-based systems that exploit the chemical diversity of amino acids to modulate biomacromolecular interactions and cellular signaling. Understanding these biomimetic design principles offers a foundation for developing next-generation functional materials that bridge molecular precision with biological functionality.