Over several decades, a technological race in environmental science battling to produce pollutant-free water resources to diminish the rate of water scarcity. Water is nature’s manifesting element which is fundamental for the survival of all living creatures. The degree of pollutants, contaminants, and toxicants released in lakes, rivers, ponds, and streams by means of human deeds causes the deterioration in the standard quality of water. An ineffective and inefficient technique of conventional wastewater treatment paved the way for the emergence of a membrane-based approach. A modern physical operation based on membranes to treat wastewater involves the process of separating a different range of particles to reclaim and reuse the water. Based on membrane processes, different separation mechanisms have been developed such as microfiltration (MF), nanofiltration (NF), forward osmosis (FO), and reverse osmosis (RO). The aim of this chapter is to provide the applications of membrane-based technology associated with the treatment of wastewater.