Nutrients, including nitrogen, phosphorus, hydrogen, oxygen, and carbon, are essential chemicals required by living organisms for growth, development, and the execution of many catalytic, functional, structural, and biochemical processes crucial for survival. However, discharging nutrient-laden waste streams into aquatic environments results in eutrophication. Hence, removing nutrients from wastewater is essential to adhere to the stringent nutrient discharge regulations. Equally important is the extraction of nutrients from waste streams to achieve a circular economy and prevent the exhaustion of limited resources. Advanced techniques for biological nutrient removal (BNR) are a key innovation in wastewater treatment to improve water quality by efficiently eliminating nitrogen and phosphorus compounds. This chapter thoroughly evaluates current knowledge regarding advancements in biological BNR technologies, exploring various traditional and innovative treatment methods widely used for nutrient removal from household wastewater. Moreover, strategies to address critical challenges such as operational stability, cost-effectiveness, and scalability are explored. In addition, the chapter delves into the environmental and regulatory consequences of utilizing advanced BNR techniques, highlighting their importance in sustainable water management and safeguarding aquatic ecosystems. The chapter underscores the significance of improvements in monitoring and control systems for maximizing BNR performance. Overall, this comprehensive manuscript underscores the critical role of advanced BNR techniques in enhancing water quality and promoting environmental sustainability.