This book examines the critical role that human behavior plays in cybersecurity. It begins by exploring the various cognitive biases and psychological factors that influence decision-making and security practices. It sheds light on how these biases can lead to security lapses and vulnerabilities, offering a foundational understanding of the human element in cyber defense. The core of the book focuses on practical aspects of addressing human vulnerabilities, including phishing, social engineering, and the impact of stress and fatigue on security behavior. It provides insights into effective user awareness training, the influence of organizational culture, and the role of behavioral economics in shaping security practices. Through case studies and real-world examples, the book demonstrates how understanding and mitigating human factors can enhance overall security. In its concluding sections, the book addresses the design of user-friendly security solutions and the importance of psychological resilience in building a robust defense. It also considers ethical issues related to privacy and manipulation in security awareness efforts. Human Factors in Cybersecurity offers a comprehensive exploration of how to improve security by addressing the behavioral aspects of cyber threats and creating more resilient systems.