This book offers a comprehensive overview of contemporary research, methodologies, and practical insights into the rapidly evolving field of unmanned aerial systems. It connects theoretical foundations with applied developments, providing a balanced exploration of design principles, flight dynamics, control algorithms, navigation, and system integration. Coverage includes both fundamental and applied aspects, including aerodynamic modeling, propulsion systems, communication architectures, autonomy, swarm intelligence, and AI-enhanced flight control. Practical challenges related to operational safety, mission planning, regulatory compliance, and performance optimization across civil, industrial, and defense sectors are also highlighted.Unmanned Aerial Vehicles: Theory and Applications features contributions from leading researchers and practitioners, offering readers a multidisciplinary perspective that encompasses engineering, computer science, and applied mathematics. It serves as a valuable reference for academics, engineers, and industry professionals seeking to deepen their understanding of UAV technologies and their real-world applications.