The sustainable development of aquaculture relies extensively on the implementation of effective biosecurity and disease management practices to mitigate risks associated with pathogens and pests. This chapter systematically examines the fundamental principles, strategies, and challenges associated with fortifying aquaculture systems through robust biosecurity measures. The exploration encompasses a comprehensive review of biosecurity principles, quarantine protocols, disease surveillance, and hygiene practices. Additionally, the chapter delves into the intricate dynamics of aquatic diseases, underscoring the imperative for proactive risk assessment and management. Specific considerations for hatcheries and grow-out systems are meticulously addressed, emphasizing the pivotal role of water quality management, stock health, and emergency response planning. The discussion extends to integrated disease management strategies, adherence to regulatory standards, and recent research advances in disease diagnosis and control. This inclusive approach provides valuable insights into emerging trends and anticipates future challenges. By synthesizing current knowledge and best practices, this chapter aims to empower aquaculture stakeholders with the requisite tools and frameworks essential for fostering sustainable disease management and bolstering biosecurity resilience in aquaculture operations.