In recent years, nutritional bars are becoming more popular health-conscious snacks for people who are concerned more about their health, especially athletes and those with hectic schedules. With this growing demand, these bars are now enhanced with natural ingredients and rich bioactive compounds. Against this background, our current study focused on the development of a functional nutritional bar using black rice as the core ingredient, combined with sunflower seeds, sesame seeds, mixed nuts, and palm sugar. The developed bar demonstrated significant functional benefits, including the presence of key phytochemicals such as flavonoids, saponins, and anthocyanin, with notable antimicrobial activity against common pathogens such as E.coli, S.aureus, and B. subtilis, with the highest zone of inhibition observed at 60 µL extract concentration. Further, the bar delivered 378 kcal, 9.66 g protein, 7.28 g fiber, 350 mg calcium, and 8.02 mg iron per 100 g, making it significantly richer in protein and minerals than conventional cereal-based bars. Compared to the control samples, the developed bar had a lower pH (4.97-5.23), reduced water activity, and better shelf stability, as well as higher sensory scores, offering higher consumer acceptability. This functional bar holds a strong potential for use in the commercial health snack market and school meal programs aimed at addressing increasing nutrient deficiency, making it suitable for athletes, adolescents, working professionals, and individuals with elevated nutritional needs.