The pursuit of sustainable lignocellulosic bioethanol has increasingly shifted toward non-conventional yeast species beyond the traditional workhorse Saccharomyces cerevisiae. In recent years, advances in metabolic engineering and synthetic biology have unlocked the biofuel potential of these alternative yeasts, many of which possess innate traits advantageous for industrial fermentation, such as thermotolerance, inhibitor resistance, and native pentose metabolism. This chapter provides a comprehensive overview of recent progress in engineering novel yeast strains (excluding S. cerevisiae) for bioethanol production. We highlight cutting-edge genetic tools, including CRISPR/Cas-based genome editing, pathway rewiring techniques, adaptive laboratory evolution, and multi-omics integration, that have accelerated strain development in non-conventional yeasts such as Kluyveromyces marxianus, Pichia kudriavzevii (also known as Issatchenkia orientalis), Ogataea polymorpha, Spathaspora passalidarum, and others. Case studies are presented featuring engineered strains with enhanced fermentation of lignocellulosic sugars and improved tolerance to stresses such as furfural and acetic acid, with some examples reaching pilot scale or utilizing industrial feedstocks. We analyze key challenges in engineering these yeasts, including cofactor balancing in pentose pathways, genetic stability, and process scalability, and explore potential solutions such as adaptive evolution and microbial consortia. Overall, the chapter emphasizes how integrating the unique physiological advantages of non-model yeasts with advanced engineering strategies can drive the development of next-generation bioethanol production. The insights and comparisons offered, including metabolic traits, engineering strategies, and ethanol yields, underscore the expanding role of novel yeasts in the bioenergy landscape and outline future directions for research and innovation in sustainable bio-ethanol technologies.