Phytoremediation leverages the natural capabilities of certain plant species to remove, accumulate, or transform contaminants found in sewage, such as organic matter, nutrients, heavy metals, and pathogens. This chapter provides an in-depth examination of the mechanisms underlying phytoremediation, the selection of suitable plant species, and its applications in sewage treatment, including the integration of constructed wetlands and other innovative approaches. It also delves into the advantages, challenges, and limitations of phytoremediation and discusses emerging trends and innovations in the field. The chapter underscores the growing importance of sustainability in wastewater management and highlights how phytoremediation, when thoughtfully employed and combined with other remediation methods, can contribute to a cleaner, healthier, and more ecologically balanced environment.