This paper explores recent advancements in sustainable commercial aviation, with a focus on innovations in jet engines and the existing regulatory framework for sustainable aviation fuels (SAF). Currently, aviation accounts for around 2.5–3% of global CO₂ emissions, emphasizing the need for cleaner solutions. SAF has emerged as a key alternative, capable of reducing lifecycle emissions by up to 80%, though challenges remain in its widespread production. In parallel, jet engine manufacturers have made notable progress in improving fuel efficiency and lowering emissions. Technologies such as high-bypass turbofan engines, geared turbofans, and hybrid-electric systems have led to significant reductions in fuel burn and emissions. Notable examples include the LEAP, Trent XWB, and Geared Turbofan engines, which have achieved fuel burn improvements of up to 20%. Despite the progress, further innovation is needed to address remaining challenges and fully transition to more sustainable commercial flight.