Electrocoagulation (EC) is an advanced water treatment technology that uses electrochemical reactions to remove a wide range of contaminants present in water, such as heavy metals, organic matter, suspended solids, and bacteria. EC discharges an electrical current through water, which develops coagulant ions from the electrodes, and these electrodes can be made up of aluminum or iron. EC produces coagulant ions, which neutralize contaminants’ charges to form flocs. This technology provides a cost-effective and environmentally friendly alternative to traditional water treatment methods by minimizing the use of chemical additives, reducing sludge generation, and improving contaminant removal efficiencies. EC has been used in a variety of industries, including textiles, food processing, metal production, agriculture, and municipal water treatment. Its flexibility and scalability make it suitable for both small-scale decentralized systems and large-scale industrial applications. While it has many benefits, some limitations exist, such as electrode fouling, high energy consumption, and challenges in scaling up. However, recent advancements, such as new-generation electrode materials, hybrid treatment technology, and coupling with renewable energy sources, show promise in overcoming these limitations and further optimizing the sustainability of EC. This chapter offers an in-depth review of the working principles, applications, and future directions of electrocoagulation as a green water treatment technology, emphasizing its potential to address global water quality issues.