Substantial amounts of nitrogen and phosphorus in discharged wastewater can cause nutrient enrichment of water bodies resulting in proliferation of algal blooms (eutrophication), which leads to multiple problems like production of algal toxins, depletion of dissolved oxygen, unsafe drinking water, and finally causes accelerated aging or death of the water body. High concentration of nitrate in drinking water can cause blue baby syndrome (methemoglobinemia) in infants. Ammonia nitrogen is toxic to many organisms. Hence, along with organic carbon removal, removal of nitrogen and phosphorus compounds is of utmost importance to protect the health and wellbeing of the ecosystem. Even though various physicochemical processes are available for nutrient removal from wastewater, biological methods are widely employed because of their effectiveness and environment friendliness. But in contrast to conventional BOD removal, biological nutrient removal is a more complex process which involves the activity of different specific microorganisms and careful control of process parameters such as dissolved oxygen, organic carbon content, forms of nitrogen and phosphorus, and so on. Conventional nitrification and denitrification processes suffer from slow growth of autotrophic nitrifiers, sensitivity to various environmental and operational conditions, and high energy requirement of nitrification process. Hence, various advancements have been made in biological nutrient removal, to overcome the limitations of conventional processes. This chapter discusses about various advanced biological nutrient removal processes such as anammox and its modifications, heterotrophic nitrification and aerobic denitrification, aerobic granular sludge-based nutrient removal, enhanced biological phosphorus removal, denitrifying phosphorus removal, and microalgae-assisted processes.