Constructed wetlands (CWs) are highly effective in wastewater treatment and have generated lines of research with a focus on technological development and implemented innovations. This work concentrates on the most recent technical and scientific advances that have obtained optimal results in the construction of CWs using sustainable materials and the use of ornamental plants and other aquatic plants. Efficiency is also documented through models and simulation with neural networks, the use of the random forest method, and the use of software such as MODFLOW, MODPATH, and COMSOL Multiphysics. The information shown is structured by geographical area and addresses regions of Africa, Asia, Europe, North America, South America, and Oceania. It is important to consider that the optimization and innovation of CW for pollutant removal may benefit developing countries that do not have sufficient infrastructure to meet the demand for municipal and industrial wastewater.