Wastewater treatment stands out as a pivotal solution for safeguarding public health and the environment. Aerobic granular sludge, as an alternative to conventional activated sludge, offers superior benefits in treatment efficacy, facility space efficiency, and energy utilization. Despite being a relatively novel approach to wastewater treatment, aerobic granular sludge technology has undergone extensive research over the past two decades. However, its real-world application has not reached the anticipated levels of adoption. Moreover, the impact of various operational strategies and processes on the properties of the granules and the treatment performance for different types of wastewater, especially regarding nutrient removal, remains somewhat ambiguous. This Special Issue discusses the performance of aerobic granular sludge for nutrient removal and pharmaceutical wastewater treatment in continuous or batch operating modes, as well as at laboratory, pilot, and even large scales. A key area of focus is the long-term stability of the aerobic granules. Additionally, this Issue explores the treatment and management of waste aerobic granular sludge using anaerobic digestion. Serving as a concise overview of the current research on aerobic granules, this Special Issue provides an insightful snapshot into the latest advancements in using aerobic granules for environmental protection.