Biogas production from the co-digestion of organic wastes offers a sustainable solution to global energy insecurity and poor waste management, particularly in developing countries such as Nigeria. Co-digestion of cow dung and waste groundnut shells under mesophilic conditions for the production of biogas was investigated. Waste groundnut shells were pretreated using dilute sulphuric acid to enhance biodegradability, while cow dung was mechanically pretreated to improve microbial accessibility. A laboratory-scale batch digester operated at 35 0C for 10 days was used to carry out the anaerobic digestion. Seven substrate combinations of cow dung (CD) and groundnut shell (GS) were examined, namely 100:0, 70:30, 60:40, 50:50, 40:60, 30:70, and 0:100. Anaerobic digestion was carried out under controlled conditions, and biogas yield was determined from the change in mass of the storage system before and after digestion. Biogas production was evaluated by gravimetric measurement, along with pH monitoring and flame tests to confirm gas combustibility. Results showed that mono-digestion of cow dung produced modest biogas yields, whereas mono-digestion of groundnut shells resulted in very low gas production due to their high lignocellulosic content. Mixing the raw materials significantly enhanced biogas yield, demonstrating a synergistic effect between substrates. The 60: 40 (cow dung: groundnut shell) mixing was found to be the optimal mixing ratio, which yielded the highest biogas mass of 22g. Flame test observations confirmed the production of combustible biogas. The research findings highlighted the potential of using locally abundant agricultural residues in conjunction with animal manure for renewable energy generation, improved waste management, and environmental sustainability. The integration of biogas systems in rural farming communities is suggested to enhance renewable energy production and improve waste management practices