The increasing concerns over climate change and air pollution have resulted in a burgeoning interest in alternative transportation technologies that mitigate Greenhouse Gas (GHG) emissions and enhance air quality. Hybrid Electric Vehicle (HEV) technologies have emerged as a viable option to these challenges, providing a more efficient and eco-friendly alternative to conventional Internal Combustion Engine (ICE) automobiles. There are still uncertainties regarding the environmental sustainability of HEV technologies, as well as constraints associated with their acceptance and incorporation into the transportation system. This study addresses these concerns by systematically reviewing current literature on HEV technologies and their environmental impact. The research methodology encompassed thoroughly examining scholarly articles, studies, and other pertinent materials on HEV technologies, their ecological consequences, and their ability to mitigate GHG emissions. The search was performed via online academic databases and relevant industry reports. The literature evaluation concentrated on research assessing HEV technologies' environmental efficacy, encompassing their capacity to decrease emissions, enhance fuel efficiency, and promote overall sustainability. An analysis was conducted on the outcomes of this research to uncover significant patterns, trends, challenges, and prospects for enhancing the sustainability of HEV technology. The findings suggest that HEV technologies can substantially decrease emissions and improve fuel economy compared to conventional ICE vehicles. It was observed that HEV can reduce GHG emissions by as much as 50% and improve fuel efficiency by an average of 20-30%. Nevertheless, challenges must be resolved, including battery technology, infrastructural development, and customer acceptability. The findings suggest that more research and development should be conducted to improve the sustainability of HEV technologies and accelerate their acceptance in the market.