Cold plasma (CP), a nonthermal technology, is revolutionizing plant protein modification for enhanced functionality in food systems. The underlying principles of CP generation and its effects on the proteins’ physical and chemical properties are discussed in this chapter. Generation of reactive gas species during CP exposure alters protein characteristics by varied mechanisms, particularly through oxidative stress, which contribute toward modulating conformational structure, bond formation or breakage, molecular weight shifts, and surface etching. Such alteration in turn leads to modulation of techno-functional properties such as solubility, emulsification, water holding capacity, oil holding capacity, thermal properties, and gelation. Application of CP-based plant protein modifications in varied food systems is discussed alongside implications on digestibility and allergenicity. CP-mediated protein modification is still in the early stage of research. Identifying and optimizing CP process parameters like treatment voltage and duration of exposure is crucial for obtaining favorable output. Ongoing research indicates the suitability of CP in tuning the functionality of plant proteins in an eco-friendly nonthermal approach, aligning with growing consumer demand for sustainable food products and processing.