Identity Security in the AI Era addresses one of the most urgent challenges in cybersecurity today: safeguarding digital identities in a world transformed by artificial intelligence. As enterprises embrace cloud technologies, automation, and data-driven systems, identity has become the new perimeter and the most common target. This book provides a practical framework for understanding how AI is reshaping identity threats and offers actionable strategies to build resilience. Drawing on real-world experience and applied research, the authors explore how to integrate zero-trust principles, responsible AI practices, and adaptive controls into enterprise environments. The text examines key issues, including adversarial AI, supply chain risks, post-quantum readiness, and identity-first security models, translating complex concepts into clear, implementable guidance. Designed for cybersecurity practitioners, IT leaders, and policy professionals, Identity Security in the AI Era delivers insight into how organizations can innovate securely while maintaining compliance and protecting critical infrastructure.