Okara is an agro-waste yielded after liquid extraction of tofu and soymilk production. It contains protein, fiber, carbohydrates, and minerals making it a potential nutritious ingredient for foods. However, several million tonnes of okara are made and discharged annually after tofu and soymilk processing, leading to environmental and economic impacts. In addition, rice is also considered a stable cereal in the Cambodian diet, so rice flour is mixed with okara flour to innovate a new formulation of cookies. Therefore, the purpose of this study was to vary and analyze the quality of gluten-free cookies using different percentages of okara flour incorporated with rice flour. The control cookie was prepared only from rice flour. The cookies containing okara were prepared by substituting the rice flour at either 40, 50, or 60% (w/w). The control sample and formulated cookies were analyzed for their physical analysis (moisture content, water activity, ash content, spread factor, and color), proximate compositions (crude fiber, fat, protein, and carbohydrate), and sensory evaluation (9 points hedonic scale). The results show that the moisture content of gluten- free cookies slightly declined with more addition of okara (p > 0.05), ranging from 1.72 to 4.37%. The water activity of cookies dropped with addition of okara from 40% to 60%, ranging from 0.2753 to 0.3175. The ash content of the control sample and three formulated cookies had no significant difference (p > 0.05), ranging from 1.18 to 1.68%. For the color of gluten-free cookies, the lightness (L*) decreased from 70.55 to 61.16, while redness (a*) increased from 6.04 to 9.24, as well as the yellowness (b*) increased from 31.85 to 34.55 when more percentages of okara flour were added (p < 0.05). In addition, the spread factors varied from 3.47 to 3.98 (p < 0.05). All cookies contain crude fiber, fat, protein, and carbohydrate of 1.68 to 4.01%, 16.16 to 21.36%, 4.62 to 13.28%, and 57.95 to 71.99%, respectively. For the result of sensory evaluation, the mixture of okara flour and rice flour with 50:50 (w/w%) had a good result for overall acceptability with an average score of 6.90 (p > 0.05). These results provide the feasibility that gluten- free cookies can be manufactured by incorporating okara flour with rice flour However, more experiments to improve the texture and shelf life of cookies by using different materials of packaging and adding stabilizers are recommended in the next studies.