The waste bioconversion offers a natural avenue for resource recovery and facilitates the eco-friendly recycling process. As rice is a major staple food consumed globally, its cultivation leads to the generation of significant biomass residues. The primary solid wastes produced during the rice production process consist of straw, husk, ash, bran, and broken rice. Biotechnological methods can yield valuable end products such as microbial biomass protein, by purifying the waste stream specifically from food processing waste. Fungi emerge as particularly advantageous for microbial biomass protein production due to their pellet or filamentous morphology, enabling cost-effective isolation and recovery from culture media, thus reducing significant fractions of capital and operating costs associated with microbial biomass protein production. Fungal biomass boasts high levels of crude protein, reaching up to 45%, with a balanced array of essential amino acids. This chapter aimed to explore the potential of fungi like Trichoderma harzianum, Candida utilis in generating fungal biomass protein from rice polishings. The review investigates that the optimal biomass yield was achieved with 5% (w/v) rice polishings after 72 hours of incubation at 28 °C. Amino acid profiling revealed abundant quantities of all essential amino acids in the final fungal biomass protein. This protein source derived from T. harzianum and C. utilis demonstrates promising nutritional value for poultry supplementation. The present chapter elucidates a comprehensive review on the practical significance of producing fungal biomass protein from rice polishings.