The growing global demand for sustainable, nutritious, and functional food ingredients has led to increased interest in plant proteins as alternatives to conventional animal-derived proteins. However, native plant proteins often exhibit limitations such as poor solubility, low digestibility, and undesirable sensory attributes, which restrict their direct use in diverse food matrices. To overcome these challenges, various physical, chemical, and enzymatic modification techniques have been developed to enhance the functional and nutritional properties of plant proteins. This chapter provides a comprehensive overview of current applications of modified plant proteins in food systems, including their roles in emulsification, gelation, foaming, and water/oil-holding capacities. Particular emphasis is given to advanced techniques such as enzymatic hydrolysis, Maillard conjugation, transglutaminase crosslinking, and high-moisture extrusion (HME), which improve the techno-functional performance of plant proteins in meat analogs, dairy alternatives, and high-protein beverages. The chapter also explores the emerging area of fermentation-aided modification and nano-structuring to improve protein bioavailability and consumer acceptability. Furthermore, it delves into the regulatory, safety, and scalability concerns that need to be addressed for wider adoption of these technologies.