Peptide secondary and tertiary structure motifs frequently serve as inspiration for the development of protein-protein interaction (PPI) inhibitors. While a wide variety of strategies have been used to stabilize or imitate α-helices， similar strategies for β-sheet stabilization are more limited. Synthetic scaffolds that stabilize reverse turns and cross-strand interactions have provided important insights into β-sheet stability and folding. However， these templates occupy regions of the β-sheet that might impact the β-sheet's ability to bind at a PPI interface. Here， we present the hydrogen bond surrogate (HBS) approach for stabilization of β-hairpin peptides. The HBS linkage replaces a cross-strand hydrogen bond with a covalent linkage， conferring significant conformational and proteolytic resistance. Importantly， this approach introduces the stabilizing linkage in the buried β-sheet interior， retains all side chains for further functionalization， and allows efficient solid-phase macrocyclization. We anticipate that HBS stabilization of PPI β-sheets will enhance the development of β-sheet PPI inhibitors and expand the repertoire of druggable PPIs.