<p>Plastic pollution has become one of the most significant threats to the environment and human health of the twenty-first century, with more than 300 million tons of waste generated annually, and conventional disposal methods are inadequate. To address this challenge, recent research has increasingly shifted toward biodegradation and upcycling as sustainable alternatives. Microbial degradation of synthetic plastics has shown advancement. This includes the introduction of novel strains like <i>Aspergillus niger</i> MG654699 for the 3.6% and 5% degradation of polyethylene terephthalate and polystyrene, respectively. Also, <i>Streptomyces</i> sp., <i>Methylobacterium</i>, <i>Arthrobacter</i>, and <i>Sphingomonas</i> have been studied to be responsible for mulch film degradation. Advances in metagenomics have further revealed the complexity of microbial consortia for driving these processes, whereas kinetic modeling has provided insights into degradation rates and conditions. Building on this foundation, artificial intelligence and machine learning are now expediting enzyme discovery, optimizing degradation pathways, and enabling intelligent waste management systems. Similarly, biosensors based on <i>Vibrio fischeri</i> and <i>Escherichia coli</i> improve monitoring by detecting plastic monomers. Beyond degradation, the integration of microbial and chemical processes has enabled the upcycling of plastic monomers into value-added products such as polyhydroxyalkanoates, vanillin, bacterial nanocellulose, fuels, and biochemicals, promoting a circular bioeconomy. These advances highlight a paradigm shift from waste accumulation to resource recovery, underscoring the potential of biotechnology and engineering innovations to transform plastic management. The review concludes by highlighting the challenges of scalability, environmental variability, and policy support while positioning biodegradation and upcycling as integrated strategies for a sustainable and resilient future.</p> Graphical Abstract <p></p>