Precise control over self-assembly of peptides into adaptable nanostructures allows for emulating the dynamic organization of natural proteins and their sophisticated biological functions. Utilization of disease biomarkers as internal stimuli for manipulating the self-assembly of peptides bestows their adaptable features with a spatiotemporal resolution to satisfy the requirement of the performance of biomaterials. Reactive oxygen species (ROS) consisting of reactive ions or free radicals are overexpressed by pathological lesions and have been recognized as one of conventional biomarkers for disease progression. Despite the progress made over the past decade in stimulus-responsive self-assembly of peptides as well as the summarization of this progress, the specific reviews focusing on ROS-responsive self-assembly of peptides remain scarce. This review summarizes the progress achieved over the past decade of the ROS-responsive self-assembly of peptides into adaptable nanostructures and their applications in biomaterials. We focus on the chemical sources responsible for the ROS-sensitive behavior of peptides, in which the chemical moieties are incorporated into peptides as side chains, terminal groups, or backbone linkages. The ROS-responsive self-assembly of peptides into nanostructures with morphologies adaptable to ROS-oxidation and their applications in enzymatic catalysis, chemosensing, drug delivery, and tissue engineering will be highlighted. Understanding the established ROS-responsive peptide self-assembling systems allows us to provide perspectives for their further development and thereby elucidate their great potential in development of advanced biomaterials.