The utilization of waste tires in combination with biodegradable polymers offers an innovative approach to sustainable material production. This strategy provides significant advantages in both environmental sustainability and functional performance. In this study, it was aimed to manufacture and characterize novel biocomposites based on the biopolymer polyhydroxybutyrate (PHB) reinforced with carbonized materials obtained by pyrolysis of waste rubbers. PHB biocomposite films containing 0.5%, 1% and 2% carbonized waste rubber (CWR) by weight were prepared by solvent casting method. The thermal properties of those new biocomposite films were examined with TGA and DSC techniques, and their structural and morphological properties were examined with IR microscopy and SEM techniques. Additionally, the electrical conductivity of biocomposites was determined. All the results obtained showed that CWR addition increased the ash yield of biocomposite films, and the highest electrical conductivity was achieved with 1% CWR addition. These findings suggest that incorporating carbonized waste rubber into PHB enhances the material's thermal stability and electrical conductivity, making it a promising candidate for sustainable and high-performance biocomposite applications