This book chapter provides a comprehensive overview of constructed wetlands (CWs) and the application of life cycle assessment (LCA) to evaluate their environmental footprint. Constructed wetlands are increasingly acknowledged as an economical and sustainable technology for wastewater treatment. The chapter reviews literature favoring constructed wetlands and identifies research gaps and future directions to enhance environmental performance and sustainability through LCA-driven optimization strategies. A methodological approach is applied to examine two CWs as case studies: a 150-kilo liter per day (KLD) sewage treatment plant and a 1.2 million liter per day (MLD) effluent treatment plant during their construction and operation phases, with the functional unit considered as 1 m3 of treated wastewater. The results reveal the total potential impact for the climate change category as 0.523 kg CO2 eq/m3 of treated wastewater for the ETP and 0.372 kg CO2 eq/m3 of treated wastewater for the STP, with higher emissions observed during the operation phases. The chapter underscores the importance of integrating LCA into the design, operation, and management of constructed wetlands, fostering a deeper understanding of their environmental benefits and supporting their widespread adoption as an eco-friendly solution for wastewater treatment in the era of climate change.