High-pressure processing (HPP) represents a non-thermal technology with significant potential to enhance the nutritional and functional attributes of proteins. As the global food market has shifted toward sustainable and clean-label alternatives, vegan protein offers ecological advantages. However, plant proteins are limited by incomplete amino-acid profile, presence of antinutritional factors and inferior functional traits. This chapter provides an overview of how HPP can overcome these challenges by inducing structural modifications in protein macromolecules, especially by altering their secondary and tertiary configuration, enhancing solubility, gelation, emulsification properties and enabling the formation of novel hydrogels. HPP has diverse applications in formulating plant-based dairy products, meat analogues, functional foods and hypoallergenic products suitable for a sensitive population. The chapter also discusses the thermodynamic principles underlying HPP, equipment design and operational mechanism, followed by its impact on protein stability, digestibility and other associated factors. While a few challenges, such as high initial investment cost, equipment cost, limited suitability for low-moisture matrices and technical complexity, require technological scale-up, HPP offers an adaptable platform for developing next-generation vegan products. Its evolutionary capacity to enhance the safety, functionality and nutritional quality of plant proteins guarantees a sustainable food system.