Microbial genetic engineering has evolved rapidly, particularly with the integration of omics high-throughput tools such as genomics, transcriptomics, proteomics, and metabolomics. These multi-omics platforms have revolutionized the design and optimization of microorganisms for boosting bioethanol production. This chapter reviews the application of multi-omics strategies in developing engineered microbes capable of overcoming traditional bottlenecks, including limited substrate utilization, low tolerance to inhibitors, and inefficient metabolic pathways. Technological advances such as CRISPR-based editing, synthetic biology, and adaptive laboratory evolution are emphasized for their role in enhancing microbial robustness and ethanol yields. Case studies demonstrate how omics-guided engineering has improved industrial strains, including Saccharomyces cerevisiae, Zymomonas mobilis, Escherichia coli, and cyanobacteria. Furthermore, industrial-scale applications underscore the commercial feasibility of bioengineered strains in second-generation (2G) bioethanol production. The chapter also addresses biosafety, environmental risks, and regulatory frameworks, emphasizing the need for ethical governance. Overall, the integration of omics and synthetic biology holds transformative potential in sustainable biofuel production, presenting a path toward scalable, efficient, and eco-friendly bioethanol technologies.