<p>Legumes are increasingly recognized as sustainable, nutrient-dense plant protein sources that can support global food security and the transition toward plant-based diets. However, the nutritional value of legumes is often constrained by anti-nutritional factors, including phytic acid, tannins, lectins, protease inhibitors, and indigestible oligosaccharides, which reduce nutrient bioavailability and digestibility. Among the available processing strategies, germination and fermentation have emerged as effective biotechnological approaches for improving the nutritional, functional, and health-promoting properties of legumes. This review critically evaluates recent advances in germination and fermentation technologies and compares their effects on nutrient composition, protein quality, digestibility, bioactive compounds, functional properties, and the reduction of anti-nutritional factors. Germination activates endogenous enzymes that promote the degradation of storage macromolecules, enhance amino acid availability, increase antioxidant compounds, and improve mineral bioaccessibility. Fermentation further modifies the legume matrix through microbial metabolism, resulting in enhanced protein digestibility, generation of bioactive peptides, improved sensory characteristics, and modulation of gut microbiota-associated health benefits. While germination offers a simple, low-cost, and environmentally sustainable approach, fermentation generally provides broader functional and physiological benefits, although it requires greater process control and economic investment. Current evidence indicates that legume genotype, processing conditions, and microbial cultures employed strongly influence the effectiveness of both processes. Despite substantial progress, challenges remain regarding process standardization, industrial scalability, product stability, and the limited availability of human clinical evidence. Overall, this review highlights germination and fermentation as complementary technologies for developing nutritionally enhanced legume-based foods and provides future perspectives for optimizing their application in sustainable food systems.</p> Graphical abstract <p></p>