Proton conduction is an essential process that regulates an integral part of several enzymatic catalyses and bioenergetics. Proton flows in biological entities are sensitively controlled by several mechanisms. To understand and manipulate proton conduction in bio-systems, several studies have investigated bulk proton conduction in biomaterials such as polyaspartic acid, collagen, reflectin, and eumelanin. However, little is known about the bulk proton conductivity of short peptides and their sequence-dependent behaviour. Indeed, several amino acids take an active part as proton transporters in biological systems. Amino acids having a phenol group, such as tyrosine have been known to play a critical role in proton-coupled electron transfer interplaying with a manganese-calcium cluster in photosystem II. Additionally, tyrosine can be oxidized and polymerized into eumelanins, which show hydration-dependent electrical current and high proton conductivity. Taking advantages of the characteristics of tyrosine, we developed a new facile strategy for fabricating peptide/manganese oxide hybrid films. The spin-coated peptide nanofilm is immersed into potassium permanganate solution to induce crosslinking and oxidation of tyrosine species, simultaneously leading to hybridization with manganese oxide (MnOx). The peptide/MnOx hybrid nanofilm can efficiently transport protons, and its proton conductivity is ~18.6 mS cm-1 at room temperature. To the best of our knowledge, no other biomaterial-based proton conductor or manganese oxide has shown such high proton conductivity. The exploration of peptide-based hybrid films as novel proton conductors has not been documented and has significant implications for understanding of the proton transport behavior in biological system and modern energy device. This study suggests that peptide-based hybrid films can be a promising new class of proton conductor.