As green biomaterial, micro-nano fibrillated cellulose (MNFC) has unique characteristics, including high strength properties, surface area, aspect ratio, crystallinity, and renewability. Associated problems of field burning draw attention to the development of rice straw-based MNFC, that can be used as reinforcement fillers for functional food packaging applications. The associated drawbacks at the industrial scale pulping process (alkaline pulping) create major hindrances for its commercial applications. To combat those problems an eco-friendly organosolv treatment has been proposed to eradicate the scaling problems at the industrial scale. Separation of cellulose fibers from rice straw was performed using one of the optimum mixtures of formic acid and acetone in the ratio of 9:1 at a temperature of 90 ℃, 70% chemical doses for 240 min reaction time in digestor. The applied low pressure and temperature in the obtained cellulose fibers result in lower energy consumption and may thus be having process sustainability on economic grounds. The development of MNFC was performed with the help of shearing as major force. The FE-SEM morphology of the developed MNFC shows that the fiber diameters are in the nanoscale. The particle size distribution by the DLS analyzer also confirms the fiber in nanoscale and has an average particle diameter of 80-120 nm. FTIR results also confirm the significant removal of hemicellulose and lignin for the developed MNFC and XRD shows an increase in crystallinity after the organosolv treatment. The developed MNFC with low lignin content may thus be used as a reinforcing additive for the development of functional packaging materials with significantly improved mechanical, barrier, thermal stability, and UV-shielding capacity. That functional packaging materials can have huge potential for the food and beverage sector.