With the growing demand for functional dairy products, integrating dual-animal proteins presents a promising strategy to enhance both nutritional value and functional properties. This study aimed to elucidate the impact of egg white supplementation on the stability, physicochemical attributes, sensory quality, and shelf-life of yogurt. Yogurt samples were prepared by fermenting milk supplemented with 0%, 5%, 10%, 15%, 20%, and 25% egg white, and subsequently evaluated for physicochemical parameters, microstructure, rheological behavior, water-holding capacity, and sensory profiles using an electronic nose and electronic tongue. Results showed that 5% egg white significantly improved yogurt stability after one day of refrigeration, whereas 10% supplementation yielded texture comparable to the control but with enhanced protein content, water retention, gel strength, and microstructural uniformity. Over 14 days of cold storage, a gradual decline occurred in physicochemical and structural parameters across all samples; however, flavor profiles remained largely stable, with no adverse effects on sensory quality except for a mild increase in acidity. These findings highlight egg white as a functional ingredient capable of improving yogurt stability and textural quality without compromising flavor, offering new opportunities for the development of high-protein, dual-animal protein fermented dairy products in the functional food industry.