The importance of clean water and the link between water and health are well-documented. Ailment and disease from the consumption of polluted water is a significant cause of human misery in the world. With the advancements in chemistry in general and in analytical chemistry in particular, our ability to detect and analyze pollutants in trace quantities has increased significantly over the years. Currently, many freshwater bodies are contaminated not only with conventional pollutants but also with several organic molecules, such as pharmaceutically active compounds, endocrine-disrupting compounds, surfactants, personal care products, and several others. These emerging contaminants (ECs) require special attention due to their toxicity to all forms of life. Besides, some of these pollutants are bio-resistant and can even sustain after primary and secondary treatments of wastewater. Advanced oxidation is a promising technique and has gained immense importance in recent years due to its ability to degrade and mineralize complex organic molecules, including ECs. Advanced oxidation processes (AOPs) rely on the in-situ generation of reactive chemical species such as hydroxyl radicals for degradation. This chapter discusses the principles and working mechanisms of various AOPs, including ozonation, Fenton, photolysis, plasma, sonolysis, and photocatalysis, and their combinations. The application of AOPs in degrading ECs such as pesticides, pharmaceutically active compounds (PACs), personal care products (PCPs), and endocrine-disrupting compounds (EDCs) are discussed. This chapter also elucidates the origin, fate, and human and ecological health impacts of ECs in water bodies.