<p>This review provides a focused overview of recent progress in the field of peptide-based supramolecular nanoassemblies, highlighting how molecular design governs the self-assembly process and determines the functional performance. Peptide assemblies, governed by a combination of noncovalent forces such as hydrogen bonding, π–π stacking, electrostatic, and hydrophobic forces, organize into diverse nanostructures, including nanofibrils, nanotubes, nanosheets, nanocages, and hydrogels. Here, we critically discuss the influence of intrinsic and extrinsic factors on peptide self-assembly and the properties of the resulting nanomaterials. This review provides insight into emerging strategies of co-assembly, correlations between structure and function, and the design of dynamic and stimuli-responsive peptide-based systems. The review also discusses the recent advances in peptide-based catalytic materials for various applications, such as carbon dioxide capture and pollutant degradation, as well as their role in biomedicine, including antimicrobial, anticancer, and regenerative platforms. By integrating these findings, this work summarizes current design principles and challenges, and outlines opportunities for developing next-generation peptide-based supramolecular materials with tunable architectures and multifunctional capabilities.</p> Graphical Abstract <p></p>