Abstract: Consumption of nutritious and useful foods has increased recently. Because cereal granola bars can satisfy the needs of health-conscious consumers by having a high content of nutrients, nutraceutical compounds, and antioxidants, their consumption is rising. The objective of this study was to investigate the optimal ratio of a mixture of Thai-coloured indica rice flour (Oryza sativa cv. Riceberry) or rice berry rice flour, Job’s tears flour, and black sesame seeds in developing a healthy cereal granola bar. Based on the experimental mixture design of 10 formulations of a granola bar, the mixture ratio of rice berry rice flour, Job’s tears flour, and black sesame seeds affected the quality of the cereal granola bar in terms of physicochemical and sensory properties, and the differences were statistically significant (p ≤ 0.05). The main ingredients of the granola bar formulation that was well-accepted were rice berry rice flour (5%), Job’s tears flour (35%), and black sesame seeds (5%). The peak viscosity of Rapid Visco Analyzer (RVA) of rice berry rice flour and Job’s tears flour was 943.67 ± 49.60 cP and 1329.00 ± 10.71 cP, respectively. This product showed the highest overall liking score of 7.27 ± 0.64 with a water activity of 0.53 and moisture content of 11.54%. These results suggest that the prepared local cereal granola bar can be a promising food product with nutritional value and antioxidant content. The addition of Job's tears flour and rice berry rice flour improved the texture of the granola bars.